Fenix BC05R V2.0 is a dual purpose rechargeable rear bike light / safety marker light. The light can be fixed to seat posts of 20-35mm diameter with the included high elasticity ladder strap, or used as a red indicator / safety marker light with the supplied body clip accessory. BC05R V2.0 features a 400 m Ah internal Li-poly battery that is charged using the supplied USB to USB-C cable and your mobile phone charger, computer or external power pack. Charging time is just 1.5 hours from a 1A charger. The light is fully weatherproof to IP66 standard and significantly improves on the original Fenix BC05R, offering 50% more brightness, 67% more run time and a wider field of view, increased from 120 to 180 degrees for added safety. BC05R V2.0 features 6 output levels:Low Constant - 5 lumens (16 hrs)Low Flash Slow - 5 lumens (80 hrs)Low Flash Fast - 5 lumens (150 hrs)High Constant - 15 lumens (4.5 hrs)High Flash Slow - 15 lumens (25 hrs)High Flash Fast - 15 lumens (35 hrs)Charging:Whilst charging the switch LED indicator will glow red, changing to green when fully charged. Battery level indicator:With the light switched off, single click the switch to check the battery status. Green light: 100 - 85%Green flashing light: 85-50%Red light: 50-25%Red flashing light: 25-0%Low voltage warning:When battery voltage drops below 25%, the battery level indicator will blink red to remind you to recharge the light. For safety, the light will work until the battery is exhausted.