Rear lights for helmets?

+1 for the Moon Nebula - fantastic light.

Another option might be Exposure TraceR - very bright, good battery life, rechargeable, will fit vents at back of most helmets but you may need to get creative with the zip ties to mount it.

Chilli technology

https://www.chilli-tech.com/bike-lights

I've had LED lights in the past on myhelmet but now have a FibreFlare across the back of my helmet held in place with zip ties an can replace the batteries without removing it from my helmet.

Moon Nebula.

Around 100 lumens but with a sensible 270 deg spread. It works more like a very brigth mini lantern/ light strip rather than a spot light.

Comes with a number of mounts that allow you to put it anywhere you want.

I can't think about a better second rear light.

Fibre flare did a helmet light, the Razor USB, I have used many other helmet lights and none were quite as good.

Tried to find it and it doesn't seem to be available anymore.

They now seem to do one called  the MVP, which looks to be far brighter and longer, 4 AAAs though.

And I cannot find anyone who sells it here either.  But you could buy it from the states.

Some people on here have not had a good time with the fibre flares but I've not had too many problems, they have remained watertight, even the original on my seatstay.

I have used the cateye loop lights, but from many years back, the newer ones didn't seem as ingenious, but could have been brighter.  My ones had a little magnet on the elastic which would activate the light with a tap.  It meant that they had no need for a waterproof rubber button, made them smaller.

Before them it was the busch and muller helmet lights, but they didn't last a season, nice idea but the seperate wires all developed loose connections.  They may have worked that out by now, mine were brand new in the late 90s/early 00s.  The seperate lights can each poke out of a seperate vent.

I am a sucker for ingenious safety products.  Other bicycle things I can humm and harr about for months but for things that might help make me that little bit safer, and that have that extra bit of ingenuity,  I can justify that much easier.

Cateye Loop lights, white for the front, red for the rear, very good items.

My LG Course came with a rear light for the helmet. It sticks on with velcro, this is it.

https://www.evanscycles.com/louis-garneau-spiderlock-vision-helmet-light-EV183136

There is a whole load of similar things.

Zip tie or velco strap