Estiq New Bike Bicycle Red LED Rear Light 3 modes Waterproof Tail Lamp Quick Release 3 Light modes: Solid, Fast-Strobe, Slow-Strobe, Water & Shock Proof - Runs on 2 X CR2023 Batteries ( included). Extremely bright LED light and aluminum alloy shell, Suitable for tube diameter :20-40mm. Designed with the waterproof, vibration-resistant and prevent-falling, it can be used in various circumstances, A good helper for riding, camping and hiking. The high-powered output will increase your visibility to the vehicles surround you in the dark. Visible 180 degrees, meaning the light is not only visible from the rear, but on both sides. No tools required, Fits any sized seat post or bike frame, 3 Strapping Sizes. Elastic Rubber stretchable to fit on almost anything! This light can be strapped on your helmet, your backpack, your bike, your stroller, and your pet's collar. Be creative and strap it on anywhere.