Allacers Bicycle Generator Mobile Dynamo Bicycle Bike 5V 1A Output Built-in 1000mAh Battery Night Riding Tool (blue)

If you live somewhere rainless or you are prepared to only use this when it is dry and don't keep it on the bike while riding it and your bike has wide tyres... 5 stars. . It rusted inside and out. Movement appears to have fatigued the metal joining the two 3.7v batteries and the plastuc case kept fouling the spokes while in charge position. ( I have a Bianchi Camaleonte sport 2 for reference.)