The strong point of this accessory is its size: 41 grams, 1.5 cm thick, 3 cm wide and 5 cm long without the caps (8 cm covered). We make a big USB key with an extra cord for attaching to a key ring, for example. Thus, we can take it anywhere and use it without fail. Indeed, other extra batteries are increasingly powerful and increasingly heavy ...
For recharging, the battery has a USB connection to a computer or wall charger. It took a little over 2 hours with a charger 5V / 1.0A.
Finally as often with this German brand, yet made in China, the appearance and finish of plastics are good.