This is a light unit contained within a silicone housing that also doubles up as the clamp.
Sporting five LEDs powered by three AAA batteries, there are an assortment of flashing modes to choose from, as well as constant light. The run times were nowhere near the claimed times though, with a little over 132 hours in flashing mode, well under the claimed 220.
Although not that bright in the light readings, the impressive thing about the Bullfrog is its visibility. The whole silicone body more or less lights up in the dark, making it highly visible from all angles. The lack of a mounting makes it simple to fit almost anywhere, although on smaller diameter seatposts it did tend to move over the bumps when wet. A white front version is also available.