This is the gold standard of blinkie rear lights. It's the same size as the PlanetBike Blinky 7, but it's incredibly bright when it blinks. Pretty much, it's got a tiny circuit board, the LEDs, and two AAA batteries and if it was any smaller, it would feel too small. There's no reflector, which generally means that you want either a reflector or a reflector-light if you want to be legal.
Oddly, they seem to use a different switch in the SuperFlash than they do in the Blinky 7, because my SuperFlash is much more likely to be accidentally triggered than the Blinky 7 was.
There are two models of it, one that has a red lens and white body and one that has a clear lens and a black body, but there doesn't seem to be any functional difference between the two.
Like all PlanetBike hardware, the packaging is minimalist in a good way. I used the plastic clip to keep it on my bag. There's also a ring to mount it to a seatpost or seatstay and an arm strap that I never used.
Mine was destroyed in a crash and I wouldn't expect it to withstand that sort of impact.