Knog Plug is a rear flasher suitable for any cyclist looking for a bright, easy-to-attach light with excellent visibility at different angles. It's made from silicone and features a domed rear lens to improve side visibility. Battery life in eco-flash mode is over 100 hours and features 5 modes. The lamp is 100% waterproof and weatherproof. 3 different lengths of silicone rubber bands are included for attachment to the handlebars. Weight: 30 g Light output: 10 Lumens Battery capacity: 220 mAh Battery life at maximum output: 1.2 - 2 hours .