I couldn't find much about the Exposure RedEye Micro light online, perhaps because it's so small and much less impressive than Exposure's other lights, or perhaps because not many people bother with a rear helmet light, or maybe because people just buy it and use it without feeling the need to discuss it online… Probably all these reasons.
But as small, cheap and simple as it may be, I wanted to put something out there for the next person who looks.
At a minimum when riding in the dark you should have a front (handlebar) light and a rear facing red light. But to make yourself more visible you can add in a light on your helmet – this is where the RedEye Micro comes in.
Plugging into the back of one of Exposure's helmet lights it gives you another red rear light, bobbing around on your helmet. It doesn't need any extra cables, or charging – as long as the main light is on, it's on (when the light is off it does light up very dimly, so personally I leave it unplugged when not in use).
At less than £15 it's a very cheap way to add an additional rear light if you already have, or are planning to get, an Exposure light. From a pure materials point of view it's a pretty expensive LED, because it's basically a single LED with a plug on the end but that argument is slightly irrelevant.
It's very bright, but no info is given on how bright and basically no info is given on the RedEye Micro product page – so you're kind of left to guess from the single photo.
I wouldn't want to have it as my only rear light if I was planning to spend any significant time on the road, but as a secondary light, or sole rear light if mostly off road and just on short sections of road to link up bridleways or whatever it'd be enough.
It doesn't have power, or any buttons, you just plug it into the port on the back of the main light and it turns on. No flashing, just steady on.
You'll need to take the rubber port cover off to get it seated in the port snugly. I did read a few comments online saying they'd had issues with it falling out but I can only imagine they didn't take the rubber cover off, as once you do that and push it into place it's pretty firmly in there.
I've stuck some leftover high vis red tape around the plastic bit of the light, to make it easier to find if I do ever drop it, as it's so small. It being so small is about the only complaint I have (which does make it a little tricky to grip to pull back out), but you wouldn't want, or need, it to be any bigger anyway so really I have zero real complaints.
So far I'd definitely recommend it and would buy one again should I ever need to.