【Bicycle USB charger dynamo】 SPINUP F12W-PRO Bicycle USB dynamo is the first bicycle dynamo with Intelligent Power Management System(IPMS). It controls power output according to your riding speed and provides touring devices with a stable electric current at 1000mA, even when you briefly stop for a traffic light. You can feel free to charge your iPhone or GoPro directly. 【What are different from regular dynamo and USB charger?】 Many people might buy a USB charger converter to connect to hub dynamo, and here are some problems : 1. Hub dynamo has lower power because the original design was for the halogen headlight. 2. Hub dynamo unable to provide enough power to USB charger and headlight at same time because it’s only 3 watts. 3. The waterproof rating may be poor of hub dynamo and USB charger combination. 4. You have to buy a hub dynamo and USB charger separately instead of once. The F12W-PRO integrated the functions altogether. 【Charging time is one time faster than hub dynamo】 SPINUP F12W-PRO USB charger provides 5W output, compare to hub dynamo with USB chager on the market only provides 2.5W output. 【Intelligent Power Management System(IPMS)】 SPINUP F12W-PRO Bicycle USB dynamo built-in micro control unit. Here are the advantages: 1.Built-in battery and chip, it won’t hurt your phone when charging at different speeds. 2.Automatically switch to low resistance mode when climbing. 3.Fixed and stable 1000mA current output. 【Auto low resistance mode】 SPINUP F12W-PRO Bicycle USB dynamo with auto low resistance mode when your speed is lower than 13km/hr, the resistance will be 1/3 of the original. When switching to auto low resistance mode, there is 1/3 power provide by dynamo and 2/3 power provided by the battery. 【Specifications】 Location: Front Output: DC6V12W Weight of dynamo: 370g Material: Out case: Aluminum USB charger: FRP(Fiber Reinforced Plastic),Aluminum Working temp.: -25°C~65°C Speed limit: 70km/hr IP rating: IPX4 Patent: Main Countries Warranty period: 1 year