Water resistant to use in dry wet weather conditions The rear bicycle light can be used by all types of cyclists at any terrain, universal fits virtually any bike frame, fork, seat post, handlebars and so on. This rear bike light will make your rides safer than ever before with a visible red light, it's one of the most needed safety accessories for your bicycle Three-mode red LED taillight with two 0.5-watt LEDs Comes with batteries, backpack clip, and new seatpost mount attaches without tools Features:Use two 1W LEDs.The wide-angle design has an effective distance of up to 1000 meters.3rd gear flash mode.Rainproof design.Lightweight and compact design. Description:Main Material: Plastic Color: Multi colorItem Size: Approx.(L*W*H)7*3.5*3cm Gross Weight: Approx.45g Package Includes: 1Pc LED Bicycle Tail Light How to open the battery back cover: Open it by hand. This product is shipped without a battery! Use 2 7 (AAA) batteriesNot Included, battery life: use some alkaline batteries, in flash mode, it can be used for about 100 hours. 1Pc LED Bicycle Tail Light