My backordered Bontrager Flare3 taillight arrived yesterday.
From the product description, I initially thought this would be a 2 AA light, but it's actually a 2 AAA light.
The light has a pretty nice clip, tall and wide. The ON/OFF button is mounted on the top. It has an audible and tactile "CLICK." Its cycle is off, steady-on, flashing, back to off.
The light also includes a rubber-strap mount to fit non-round seatposts (e.g. Trek Madones), two sizes of round clamp-on mounts, and they've included a threaded hole if you want to bolt the light onto a reflector bracket.
The light has two large emitters facing the rear, and two smaller LEDs that aim sideways. All of them are red. The big ones are claimed to be 1/2-watt emitters.
The beam pattern is, uh... unusual. I bet the BBC could use this on the Doctor Who set somewhere. EX-TER-MIN-ATE!!
In steady mode, the light runs just one of its two main emitters, and doesn't run the side-facing emitters at all. I suppose they don't want to use both of the big emitters at once because it would result in short runtimes, but I would've at least added the side emitters.
In flashing mode, the light blinks one main emitter, then multi-flashes the side emitters, then blinks the other main emitter. Since it never fires both main emitters at once, there is no logical reason for it to have two of them (other than marketing, of course). Visually, I don't think the flash pattern is as noticeable from the rear as the ubiquitous SuperFlash, which double-strobes the main emitter. It does seem a little more noticeable than a SuperFlash from the side.