The Glowspek PREMIER edition pedals was designed for one primary function-SAFETY. No Batteries needed! This PREMIER pedal contains 8 LED lights on each pedal. The light activates as the user spins the pedals, without any batteries needed. It provides 1,500 feet of nighttime visibility! Product Dimensions:L 4″ x W 3 1/8″ x H 1 1/4″ Bolt Dimensions: Crank 9/16” for thread Weight: .45 lbs.