The new Vis 180 degree tail light is the best performing rear light on the market Uprated to 50 lumens for Winter 2012 it delivers 10 times the output of almost everything else The powerful red light sweeps a broad beam to the back Directional side amber beams alert overtaking cars The tool-less pivot lock mount features multiple locking positions easily attached on seat stay seat post or messenger bag & removes easily for safe keeping or charging Micro USB (Universal Serial Bus) port accepts charging from most mobile phone chargers or any USB (Universal Serial Bus) port 5 hour recharge time Li-ion battery Run time High Solid: 4 hours High Pulse: 8 hours Flash 20 hours System weight: 110 grams