This 6" customizer allows you to use the height, width and depth of an item to create a cage behind the rack panel.  This cage is mostly open on the sides and back and is solid on top.  The front opening of the cage mount frame can be adjusted on all four sides to cover up things like curved edges and feet.

 If your item needs the top or bottom for ventilation you will likely want to add some primitive modifiers to the finished .stl before printing.  PM me for help with that.  I may make a new customizer with top ventilation if there is enough demand.