lock mode feature keeps the lumina micro 650 headlight securely powered off during transport or storage. unlock / lock the light by simply holding the power button down for 8-10 seconds. important to note that niterider uses this key feature after assembly and production to prepare for transport. the light is set to lock mode at the factory, unlock before use. optimal viz for increased visibility while out on the roadways. cars and motorcycles are incorporating daytime running lights for increased daylight visibility. and with drivers more distracted than ever, we think cyclists should as well low battery indicator is cleverly designed into the power button. lit in blue indicates a good battery level remaining. lit in red indicates that the battery level is below, less than 20% remaining. durable and long-lasting rugged design of the lumina micro 650 with dupont fiberglass reinforced nylon housing provides cyclists with the most durable, reliable and best performing lights in the market. rely only on quality lighting systems