LOCK MODE FEATURE keeps the Lumina TM Micro 850 headlight securely powered off during transport or storage. Unlock / Lock the light by simply holding the power button down for 8-10 seconds. IMPORTANT: THE LUMINA TM MICRO 850 IS SET TO LOCK MODE AT THE FACTORY. UNLOCK BEFORE USE. CONVENIENT USB RECHARGEABLE makes it easy to charge, eliminating the need to replace batteries on a regular basis. Can be recharged from any powered up computer, device or AC wall adapter. USB charging cable included. LOW BATTERY INDICATOR on the Lumina Micro 850 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, the Lumina TM Micro 850 features a 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