4.8 kgs..??? thats quite lite. I heard multiple engines only on planes. I got to know a snake with two heads one at each end is called a double engine. Correct me if Iam wrong.I dont have much knowledge as the guys in this forum have.Not certainly enough knowledge to fool people and extract some money. And by the way, that poor snake would be confused as to which direction to go. probably that's the reason it costs so much?