This is an alternate glass bed holder for glass cut to a larger diamter than what was expected. It is designed to mount on the lower rails of Steve Grabers' excellently designed Cerberus Delta printer found here: http://grabercars.github.io/CerberusPrint with enough infill to make yourself comfortable, the glass really isn't that heavy and distributed over 3 - 4 mounts. I used 4 to have one on each side of the power switch I installed in the front. Slide on to rails and set your glass on it. I'll probably add double sided tape to better secure it.