Portland Design Works offers the power of an LED automobile taillight in a smaller package.
Includes Stayputnik quick release taillight mount, fits up to a 31.8 seatpost and attaches without tools
1.0 watt Japanese LED: same LED used in car taillights
Features crescendo flash pattern
Run time is 50 hours
Two AAA Alkaline batteries included
Requires the on/off button to be depressed for 1.5 seconts to be turned on or off so the light doesn't unintentionally get turned on when stowed in a bag or satchel