Amazon.ca Product Description The BV LED Taillight mounts quickly onto bicycle seat posts. Great for cycling at night or in places where visibility and safety are a concern. Visible to motorists over 1500 feet away. It features a quick-release system that makes it easy to remove from the seat-post bracket. When leaving your bike, prevent theft by taking your light with you. The quick-release clip is also attachable to gear bags, allowing for more flexiblity in light placement. 3 modes (steady, flashing and blinking) help to alert drivers of your presence on dark roads. It is angle adjustable and fits most seat posts (rubber sizing shims are included). Up to 80 hours. (Batteries not included) Note: When installing the light onto the mount, please ensure that there is a click indicating that the locking tab is in place. Please contact us at 877-985-5888 if further instruction is needed. Specifications 3 mode taillight: steady, flashing, blinking Run Time: 35 hours steady, 80 hours flashing (Tested using standard alkaline batteries) Lumens: 15 Batteries: 2 x AAA (not included) Water resistant: Yes Mount: Bracket Taillight (plus quick-release clip) Dimensions (without mount): 2.5" x 1.5" x 1" (6.4 cm x 3.8cm x 2.5 cm) Weight (with mount): 1.4 oz (40 g). From the Manufacturer The BV LED Taillight mounts quickly onto bicycle seat posts. Great for cycling at night or in places where visibility and safety are a concern. Visible to motorists over 1500 feet away. It features a quick-release system that makes it easy to remove from the seat-post bracket. When leaving your bike, prevent theft by taking your light with you The quick-release clip is also attachable to gear bags, allowing for more flexibility in light placement. 3 modes (steady, flashing and blinking) help to alert drivers of your presence on dark roads. It is angle adjustable and fits most seat posts (rubber sizing shims are included).Up to 80 hours (Batteries not included), Note: When installing the light onto the mount, please ensure that there is a click indicating that the locking tab is in place. Please contact us at 877-985-5888 if further instruction is needed. Specifications 3 mode taillight: steady, flashing, blinking, Run Time: 35 hours steady, 80 hours flashing (Tested using standard alkaline batteries), Lumens: 15, Batteries: 2 x AAA (not included), Water resistant: Yes, Mount: Bracket Taillight (plus quick-release clip), Dimensions (without mount): 2.5-Inch x 1.5-Inch x 1-Inch (6.4 cm x 3.8cm x 2.5 cm), Weight (with mount): 1.4-Ounce(40 g).