The Blink/Steady is the most tamper-proof light on the market. Users attach the 2.1-ounce LED lamp with two types of fasteners—an Allen and a 2mm Torx—which makes removing it a difficult, time-consuming task. A light sensor signals the Blink/Steady to turn on at night, and an accelerometer gives the okay to turn off once the bike is back home. Blink/Steady bike light $95