So, fast delivery (typical Amazon), price-performance ratio = good ... But unpacked, reingesteckt, half again fell out. Not like only good response to the ground. In the original the battery lasts by itself and on the go, there is an additional locking. When MUST replacement battery this lock to be closed, otherwise the battery falls out. but when you first start it worked anyway, and because I desperately need it for a longer ride, I do not send him back ... Let's see how long he is keeping and if he gets stuck mobile or even permanently lose contact ...