Moon Gemini Rear Light

Moon's Gemini is a featherweight USB rechargeable rear light that clips on easily and is bright enough for urban commuting. The small single button is surprisingly easy to find in big gloves.

The Gemini is a new addition to Moon's Tail Light range and benefits from many of the features of its more expensive big brothers. It has a spot angle of 95 degrees at 10 metres, giving an effective span of 22m. The total angle is helped by the two single LEDs, resulting in a full 360 degrees, very useful for urban riding. The brightest 20-lumen constant is also perfect for partially lit commutes; I prefer a slightly brighter rear for my unlit rides, but this also works well here as a backup or secondary light.

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The Gemini clipped easily onto my seatpost and I quickly toggled through the seven modes to find the 'day flash' setting, perfect for even a bright, sunny morning ride to work. While it's currently still daylight for my commute, I've only really needed this day flash mode; it gives a sharp 30-lumen flash, with a quoted 30-hour run time from its rechargeable lithium polymer battery (3.7V 300 mAh).

The run times are pretty much spot on; having left my light on in the shed overnight, I was surprised to find it still flashing the next afternoon. As with any light, a constant beam does run down the battery at a much faster rate – 1:40 (claimed) when running the light's brightest constant 20-lumen setting; my light lasted 1:44 on the same setting from a full charge. This is still more than enough for most commutes, at least one-way, so you could charge it during your working day if you have that option, ready for the ride home. Charge time is only 2 hours from flat, a little longer if charging from a laptop.

Connecting the light to your bike couldn't be simpler thanks to Moon's universal mounting bracket. The RB-22 is compatible with all of Moon's lights, so switching this out for something bigger is easy. The catch feels sturdy and I've had no worries about the light bouncing out on rough terrain. I tested my theory on a cyclo-cross ride and it stayed put. Top marks!

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Build quality is really rather good too, with no part of the light or its mounting bracket feeling poorly made. The CNC aluminium heat sink casing means bashes shouldn't ruin your light.

I was initially concerned by the single button on the rear of the light – small buttons are usually difficult to find in thick gloves – but the rubberised material and its protrusion from the light body meant I had no problems. The button also makes a positive click that helps when trying to cycle through settings on the move.

Overall, this is a great little light to help make sure you're seen during the day and under streetlights, or as a secondary light in the dark.

Verdict

Perfect for day-time and street-lit commuting or as a secondary/back-up option