Material: Plastic Fit Type: Universal Fit Vehicle Service Type: Passenger Car, Truck, Bicycle, Motorbike Number of Pieces: 20 Shape: Wheel Item Weight: 4.6 ounces Package Dimensions: 6.46 x 4.25 x 1.18 inches Batteries: 3 Lithium Metal batteries required Position: Inside Bulb Type: LED Please note there is a piece of paper in the battery case that needs to be removed before use. Sometimes it may not work immediately after removing the paper; in such cases, install them on the valve stem and begin riding—the lights will activate when the wheel turns. About this item: [Wide Application] Wheel lights are compatible with various bicycles, automobiles, motorcycles, mountain bikes, road bikes, and children's bicycles equipped with American-style valve stems. These wheel lights enhance visibility during nighttime and in adverse weather conditions from all directions. [Alert Function] The LED flashing tire light serves as a safety warning and decorative feature for night driving. It improves visibility in low-light and poor weather conditions to help ensure rider safety. [Waterproof Durable] These tire valve lights are made of high-quality plastic material, free from toxic chemicals and unpleasant odors. They are designed to withstand rain and snow; however, do not submerge them in water. Built for durability, they offer long-lasting performance. [Easy To Install] No tools required. Simply screw the lights onto the tire valve stem. This is a vibration-activated LED light that turns on automatically when the wheel rotates, creating an attractive visual effect.