Bicycle Bike Rear Safety Warning 5 LED Tail Light - Red Light - 7 operation modes: full light, fast flash, slow flash, slow left to right flash, slow right to left flash, fast left to right flash, slow left to right right to left flash, off - L2-1/2" x W1-7/8" x D1-1/4" - powered by 2 x AAA battery (batteries included) - brand new, never used - $10 firm