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WUBEN G5 Honest Review | Can a 52 g Keyring Light Get You Up a Mountain After Dark?

2026.07.27

Mountains at night are frightening. That doesn't change. What this hike taught me is how much of that fear simply lifts when you can see your own feet clearly.

The light in my hand was a WUBEN G5 — 52 grams, small enough to live on a keyring, with a claimed output of 400 lumens. I took that number onto a properly dark trail to see what it was worth. The setting was Shonandaira, a hill climbed from Oiso in Kanagawa, on a midsummer night. Once the street lighting ran out, how far would this one small light carry me?

Here's my conclusion up front: the G5 will not replace a proper hiking headtorch, but as an everyday carry light, a backup and an emergency-kit item, it is exceptionally well judged.

This light was supplied to me by WUBEN. What follows is what I actually found on a dark trail, the good and the less good alike. Where the manufacturer's claims and independently measured figures differ, I give you both.

The moment the street lights end, the mountain becomes a different place

I started at Oiso station. It was 30°C at the trailhead — a night hike, and I was already sweating. Any hope that darkness would bring cool air was dispatched fairly quickly.

There are street lights as far as the start of the trail, and while there's light, the fear stays at about half strength. Then you step onto the path, the town's glow disappears behind you, and the mountain becomes somewhere else entirely. Trees shifting. The dry crackle of leaves underfoot. Sounds you would never register in daylight suddenly have your full attention.

That's when I switched the G5 on. My first thought was simply: *this small, and it reaches that far?* It was clearly throwing more light than its palm-sized body had led me to expect. With the ground at my feet and the trail ahead both lit, the unease I'd been carrying quietly drained away.

Further up I turned it off for a moment, out of curiosity. What was there was genuine, total darkness — I couldn't see my own toes until my eyes adjusted. That was the moment it clicked that the value of a light isn't measured in lumens, but in the gap between that darkness and what you can see with it on.

Oiso station to Shonandaira | a night-view hill you can reach by train

The route runs from Oiso station over Hajiroyama (111 m) and on to Shonandaira. Shonandaira is a hill of roughly 180 metres, and its summit is a broad viewing terrace known as Senjojiki. It's on Japan's list of 100 best night views, and a thoroughly established date spot in Kanagawa.

Signposts appear at the junctions — "Shonandaira 1.2 km" and so on — so even in the dark there was very little risk of going wrong. At one point you can choose between a steep flight of steps and a gentler path. In pure distance, it is not a long walk.

But a short route is not the same as an easy one. This was straight after the end of the rainy season: hot, humid, sweat that wouldn't stop, and the low-level tension that darkness adds. For the distance involved, it took a surprising amount out of me. People often choose night hikes to escape the heat, but on a low mountain in high summer the temperature simply doesn't drop far enough. Carry as much water as you would in the middle of the day.

The view from Senjojiki was worth every bit of the sweat. Town lights spread out below you, and if you turn your back on them and kill your own light, there are stars overhead.

WUBEN G5 specifications | keep claimed and measured figures separate

Here are the basics. When choosing a light, the trick is always to keep the manufacturer's claims and independently measured figures in separate columns.

• Maximum output: 400 lumens claimed / roughly 278 lumens measured in independent testing (30-second ANSI)
• Weight: 52 g claimed (around 53 g measured, battery included)
• Size: 62.1 × 37 × 13 mm, flat and slim. It won't roll away from you
• Charging: USB Type-C, around 1.5 hours claimed (about 1 hour 20 measured)
• Ingress protection: IP65 — fine with rain and splashes, not rated for submersion
• Colour of the light: daylight white, measured at roughly 5,800–6,900 K. Colour rendering is low at around CRI 65
• Price: ¥5,850 (manufacturer's price at time of filming)

In other words, the 400 lumens on the box is an instantaneous figure at switch-on; in real use you should expect somewhere around 280. That said — is 280 lumens not enough? It absolutely is. For lighting the ground at your feet and a few metres of trail ahead, I walked comfortably. Having accurate expectations matters far more than having a big number.

Three features that genuinely earned their place on a dark trail

1. The head rotates through 180°

The most useful thing about the G5 is that its head pivots. Holding the body still, you can aim the beam wherever you need it — from your feet, up to a signpost ahead, up again to a branch overhead — without twisting your wrist. On a dark path, that turned out to matter far more than it sounds.

2. The clip and the magnetic tail

The clip adjusts to three positions and grips a cap brim, a chest pocket or a rucksack shoulder strap. Being able to convert it into a hands-free work light wherever you happen to need one is a genuinely good piece of design, on the hill or off it.

There's also a magnet in the tail, so it sticks to any steel surface. Unglamorous, but when I was reorganising my pack between filming, never having to hunt for somewhere to put the light down was quietly excellent.

3. Red light (RGB) and a physical lockout

Stare into strong white light at night and your eyes stop adapting to the dark. Alongside white, the G5 runs seven RGB colours, and the red mode lets you check things up close while keeping your dark adaptation intact. That's the mode you want in a tent, sleeping in a car, or reading a map while you look at a night view.

Less exciting but arguably more important: the sliding physical lockout. It stops the light switching itself on inside your pack and leaving you with a flat battery at exactly the wrong moment. That's the detail that tells you this was designed as something you actually carry every day.

The honest drawbacks

It isn't all good news. These are the things worth knowing before you buy.

• High output holds for about an hour. High and turbo modes step down early for thermal reasons. You do not get the same brightness across several hours of walking.
• The light is cool and blue-ish, with low colour rendering. CRI 65 is not a light that shows you colours faithfully. It's the wrong tool for reading colour-coded maps or looking at autumn leaves.
• The battery is internal and not user-replaceable. You can't swap in a fresh cell to revive it, so on longer days a power bank becomes a prerequisite rather than a luxury.
• IP65 does not mean "you may drop it in water". Rain and splashes are fine. Submersion is not covered.

And the most important point of all: the G5 is not your main hiking light. For walking through the night, or on narrow mountain paths, a headtorch that leaves both hands completely free should be the star of the show. The G5 is happiest as the second light standing next to it — the one you always happen to have.

G5 vs X4 vs X1 Pro | what three lights side by side actually tells you

In the second half of the video I put the G5 next to the WUBEN X4 and X1 Pro, both of which I've reviewed before, and compared their beams. Framed as "which job suits which light" rather than better and worse, it comes out like this.

• G5 (400 lumens claimed, 52 g): everyday carry, backup, emergency kit. Its real weapon is being light enough to leave clipped to your keys or your pack permanently
• X4 (1,500 lumens claimed): a good balance of output and portability — enough to lead a night hike or a camp
• X1 Pro (12,300 lumens claimed): the most powerful of the three by some distance. When you need to reach a long way into the dark, the reassurance is in another league

The choice is simple. G5 if you want something always on you, X4 for the hiking balance, X1 Pro if raw output comes first. I use all three, chosen by the job.

If you're considering the X1 Pro | a 15% discount code from WUBEN

WUBEN have supplied a 15% discount code for purchases on Amazon.co.jp.

• Code: IWSK2026
• Valid: 6 August 2026, 18:00 – 15 September 2026
• Applies to: the X1 Pro only (not the G5 or X4), on Amazon.co.jp

Enter the code in the discount code field at checkout. Note that this is the Japanese Amazon storefront, so it will be of use if you're shopping in Japan.

How I think about lights for night hiking

A short aside on walking in the mountains after dark.

• Always carry at least two light sources. Headtorch as the primary, handheld as the backup. Either one can fail and you keep moving.
• Treat a power bank as part of the system. A rechargeable light is finished when the battery is. If it charges over USB-C, a power bank becomes your spare cell.
• Brighter is not automatically better. When you're taking in a view or stopped for a rest, a modest mode or red light is kinder on your eyes and on anyone with you. A light with proper stepped output is the one you end up using most.
• Don't strip your kit down just because the mountain is low. Short distances still expose you: darkness reliably drains both energy and judgement. Water, an insulating layer and a map come with me exactly as they would in daylight.

The Yokokujiyato burial caves, in the valley on the way down

Descending from Shonandaira back towards Oiso station, you pass an unusual historic site: the Yokokujiyato cave tombs, designated a historic site by Kanagawa Prefecture.

They are graves from the Kofun period, cut horizontally into the hillside, arranged across four tiers of the slope. What makes them interesting is how the shape changes. The oldest are carefully cut in a gabled form, deliberately imitating a house with a roof. As the centuries pass they become domed, and eventually simplify into plain arched tubes. Simply looking along the rows, you feel more than a thousand years of time passing.

The information board notes that this valley was once known as the valley of graves. Somewhere ancient people came to see off the people they loved — and knowing that, at night, the same view reads completely differently. I walked down towards the station giving the quiet its due.

In summary: the G5 is a light you can forget you're carrying

I still remember the depth of the relief when I got back to Oiso station. A short distance, and yet the heat and the tension of the dark had thoroughly emptied me. It was still a night I'm glad I had.

If I had to sum the WUBEN G5 up in one phrase, it would be preparedness you can forget you're carrying. At 52 grams it costs you nothing to leave clipped to your keys or your pack, which is precisely why it's in your hand when you genuinely need it. Around 280 measured lumens is a modest figure, but it was more than enough to light the ground and take the fear out of it.

It's a good fit if you:

• want a small light permanently on your keys or in your bag
• want a light backup and close-work light on the hill, separate from your headtorch
• want one rechargeable light in the house for power cuts and emergencies

If what you're after is the main light for walking through the night, buy something further up the range like the X4 instead. When you need absolute output, it will serve you better.

Full specifications and where to buy are linked in the video description too. Whether or not there's a small light in your pocket when you walk a dark path — that difference is far bigger than it sounds.

※ This article is based on a video made with a product supplied by WUBEN. Figures are the manufacturer's claims and independently measured values; real-world performance varies with conditions.

※ As an Amazon Associate, Yoshimi Iwasaki earns from qualifying purchases.

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This post contains affiliate links. Prices and specifications are as of the video's publication date. Most items are sold in Japan.

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