Keep your dog visible on nighttime walks with the Coastal USB Light-Up Neck Ring, a waterproof safety light that provides 360-degree illumination. It snaps on to be worn alongside your dog's collar and trims easily for a custom fit. Cycle through three light settings with a single power button; enjoy up to 5 hours on flashing or 3 hours on continuous before a fast 40-minute USB recharge (charger included). Sizes: Medium fits necks up to 16 inches; Large fits up to 24 inches.