The Blinky 3 Mounts to either your seatpost or seatstay. Three super-bright LEDs and a built-in parabolic reflector will help you to be seen from up to one mile away.
Also can clip to your belt, bag, jersey, seat pack, rack-top bag, and other manner of items such as will receive the clip.
You want more versatility. Seriously? You do? Okay, how about the Blinky 3H-3 LED Bike Tail Light with Helmet Mount?
Save when you buy a this tail light with a Beamer 1 Headlight as a set: Planet Bike Beamer 1 & Blinky 3 Light Set.
Busch & Müller Tail Light Bracket T For Rear Rack With No Hole
Planet Bike Rack Hardware
Planet Bike Spot Micro 1 Bike Headlight