Exposure tracer usb rechargeable rear lighta convenient led rear light ideal for any commuter that can be recharged and comes with a day light visible mode.rechargeableexposures tracer rear light comes with a rechargeable lithium ion batter with micro usb charging cable that lets you charge the light from any standard usb port. An integrated fuel gauge also lets you know when its time to charge.daybrightto keep you visible, day and night, the light comes with a specialised daybright mode which will help you stay seen even in direct sunlight. This is especially great for when cycling through built up urban areas where youll be dealing with multiple lanes of motorists and other road users.technologiesdaybrightbespoke pulse pattern designed for daylight use which is more conspicuous than a regular pulse and visible from over a kilometre away, even in the brightest conditions. Daybright mode will get you noticed. Be seen, be safe.fuel gaugeusing a traffic light system remaining runtime is easily monitored at a glance so youre not caught out.  the colour feedback is also used for mode selection, before defaulting back to runtime. Intelligent thermal management itmpatented circuitry within the light will reduce power to the leds, if they go beyond the optimum temperature, keeping the light as efficient as possible to maximise output and battery capacity.in the boxtracer rear lightseatpost bracketmicro usb charge cablequick start guidefeatures75 lumens maximum light outputred xpe r cree leddaybright modecable free designrechargeable lithium ion batteryintegrated fuel gaugeanodised 6063 aluminiumipx6 water resistanceintelligent thermal managementweighs 35gdimensions 57 x 28mmbuy exposure lights from chain reaction cycles, the world's largest online bike store.