Specifications: Battery Type: 2*AAA ( not included) Light color: RED Casing color: black & red. Size: approx. 8.6 x 3.1 x 4.9cm. Bicycle mount fits approx. 20-36mm diameter tubes Features: 5 bright Red LEDs and 2 laser beam design can keep a safe area for cycling or riding at night. LED indicators and laser beams can operate simultaneously. The "bike" Logo projection from back will keep you more visible, eye-catching. With an adjustable clamp, easy to install and remove. Automatically turn on with parking more than 5 minutes. Waterproof design. The LED indicators 5 modes: Always bright/ Fast flash /Slow flash /up to down /down to up. Package Include: 1x Laser Bike Tail Light 1x Bicycle Mount Operation Instructions: Press LED button and hold for 2 seconds, LED will turn on/off. Press LED button and then release quickly to set a mode. ( 5 modes available) Press LAS button and hold for 2 seconds, laser light will turn on/off. Press LAS button and then release quickly to set a mode.( 2 modes available). Attentions: Please use high quality AAA batteries for this light and do not mix using old and new batteries. Take batteries out if long time not using the light. Please do not point the laser light directly to eyes, especially to children’s.