Specifications Key Features :Bicycle Tail Light, Rear Lamp Battery :2 x CR2032 battery (not included) LEDs :2 LEDs Light Color: Red Function :Waterproof 4 Kinds of Switch :Full light, flash, slow flash, off Button: One-Touch switch design, easy operation Body Material: Flexible waterproof silicone Lit Time :All the sustainable use of light 35 hours Scintillation sustainable use of 160 hours Body Color: Black Weight: 0.78 oz Dimension :3.62" x 1.18" x 1.18" (L x W x H) You can use it for :Outdoor activities, like biking / hiking Package Includes 1 x Waterproof Double Red LED Light with Black Silicone for Bicycle