I got a bit tired of having to adjust the printbed level under my mendel prusa printer. Thus I created 4 of these wheels. They have a M3 nut in the middel. Jus print out 4 of them and press in an M3 nut. That is all. Replace the washer and nut with this wheel and adjusting the printbed level is a sinch.a) print 4 of these wheels b) press in an M3 nut c) replace the 4 M3 nuts now holding the printbed in place with these wheels