We say: Such a goog light. 200 lumens, 270 degree visibility.
Pair with the saddle rail mount (available as a seperate part for about a fiver) for the cleanest, most optimal installation.
A constant 50 (group ride) or 100 lumen mode, or a 200 mode flash (along with two others). It remembers the last mode you ran, and the power button lights up to indicate the charge when you turn it off and on. Basic stuff really, but not every light does it or quite so well.
An obvious choice this one.
They say:
FEATURES
Maximum output to 200 lumens
ANSI-Standard certified lumen output and runtime
Waterproof to IPX7 standard
Two-lens focused and dispersed optics with side light design for over 270-degrees of visibility
Power status indicator alerts remaining run-time before powering off
Light memory mode
Compatible with Rev Comp, Compel, Roost and Prompt series helmets
Compatible with saddle rail mount, providing optimal angle for visibility