371541 Features: 2 drops salt water can drive the car 20minutes， it really did. Assembly it according the manual step by step. it is very detailed Attention: add salt to tap water or distilled water at ratio of 1 salt : 5 water. any percenage ratio from 20% to 99% is ok. but 20% will be more effecient remove the FC module and put a Air cathode ( black side up) ， and then a nonwoven fabric second ， the third ， when i do this step i made a mistake i put the same side magnesium sheet. Guess what happened. it smoked. i was amazed. so i metioned this， in order to avoid this case. this is good for children lightning their wisdom. Package list: 1x motor connector 1x gear 1x gear shaft 1x round shaft 1x cathode plate 2x non-manufacturing cloth 3x anode metal sheet 1x plastic dropper