I understand that you can not expect top quality for 6.40 but this product can be very dangerous: I had bought the engine (as well as other buyers here) for a mobile so the kids have more entertainment. Equipment has been delivered quickly and I have but it loaded with a brand Varta battery fortunate suspended not just because it happened does not should happen: the engine was probably a short circuit and after a few minutes the battery has burst and leaked. Had I it would be suspended, the battery fluid dripped directly to the children ... So you better stay away from this electronic waste!