the top cap is very thin and most of my atties screw past the threads meaning it wobbles about on the mod unless you get a spacer of some description. the tubes dont semm to be perfect as in when you change a battery or use a different type battery you have to adjust the magnets and i was also given some magnets to build batteries up so they fit. i also notice when you adjust the magnetic firing switch and screw the tubes together the magnets move so you are firing constantly or the throw is too far.
but as isay when you get it working its brill and a good kick