Bicycle Alarm Disc Brake Electric Lock with Keys Motorcycle Alarm Brake Rotor Padlock Aluminum Alloy Motorcycle Bike Accessories. Features: Weatherproof Security, Universal Fit, Keyless Convenience, Long-Lasting Battery, Loud Alarm System. Specification: Origin: Mainland China, Main Material: Aluminum Alloy, Color: Black, Red, Blue, Green, Yellow, Size: About 8cm (3.15in)*6.3cm (2.48in)*3.5cm (1.38in), Net Weight: About 198g, Battery: 6*Button Battery.