Features: wireless brake light with easy installation No.1 in rearlight field.also responds whin hitting very big bumps and dips on the roads, work with rechargeable batteries without brightness sacrifice No.1 in rear light field auto power-on capability (within 30 sec of ridding)auto-off capability (when staying still over 4 minutes) No.1 in rearlight field, low power indication (when power is below 2.3V)wider visability design and weather resistant. equipped PWM / switching technology to remain stable brightness during low power condition and save power up to 30% No.1 in rearlight field.
Specifications: 5 ultra-bright red led S-2XAAA battery.