Moon MK II Rechargeable COB Rear Light – review

Bright rear light and decent value, too

The Moon Mk II Rechargeable COB Rear Light brings together a maximum output of 50 lumens, a range of modes and wide-angle visibility in a compact and easy to use package.

At first glance the Moon Mk II looks much like many other lights I have used in the past. The rectangular shape sits nicely on the seatpost without being imposing, something which always pleases a minimalist like myself who wants to keep the bike as clutter-free as possible.

Mounting to the bike comes through one of three rubberised backings, designed for regular or two types of aero seatpost. The backings can be easily changed but are also liable to becoming detached from the light when it’s not on the bike, as I found when I had it in my saddle pack as a spare on a long ride.

The Moon Mk II uses a simple o-ring mount to attach to the seatpost

However, when mounted to the seatpost this isn’t an issue as an O ring keeps everything in place and the light secure against the seatpost. The O ring pulls the light in towards the seatpost with the rubber backing sandwiched between the two.

The light has a maximum output of 50 lumens, which makes it one of the brighter rear lights out there. Run time is limited to one hour on the most powerful ‘overdrive’ mode, so you’ll have to use that sparingly or on shorter rides, but otherwise there are seven alternative settings: high (25 lumens, run time 2h 15m), medium (12 lumens, 4h 30m), low (six lumens, nine hours), 100% flashing (50 lumens, 2h 10m), 50% flashing (25 lumens, 4h 25m), 10% flashing (five lumens, 20h 40m) and strobe (ten lumens, 10h 40m).

That ensures there are plenty of options depending on the conditions, where you’re riding and battery life, though I found the lowest settings, with six lumens when static and five lumens when flashing, could result in the light getting a little lost when riding in the city. I found the 25-lumen flashing mode to be most useful and just over four hours of run time meant I had to charge it every two or three days when commuting.

Otherwise, the light has impressive 300 degree visibility, meaning that it can be seen from almost all sides, so cars and other riders shouldn’t struggle to see you regardless of how they approach.

The light has a maximum output of 50 lumens


While I didn’t find the lowest settings particularly useful, there are a range of practical options and the wide-angle visibility of the light is excellent. It’s easy to fit and compact, too. Battery life is limited on the most powerful settings and it would be nice to have a firmer connection between the rubber backing and the light, but aside from these small issues, it’s a good, well-priced rear light.


– Decent value
– Easy to fit, mounts for regular and aero seatposts
– Bright and wide-angle visibility


– Battery life in most powerful modes could be better
– Rubber backing prone to coming off when light is not mounted

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