The Revolution and RXL do not have a power switch (you need to manually unplug the power cord). This part is intended to fix that shortcoming. Designed to be printed without supports - just slide the small snap-in piece into the larger main body piece. Individual STL files provided as well as pre-sliced GCODE that should work reliably well for brand-new RXL/Revolution printers right out of the box.The rocker switch should fit very snugly. This bracket is designed specifically to fit the RR1 series from E-Switch (http://www.digikey.com/product-detail/en/RR111C1121/EG4772-ND/2116251). Mostly because I happened to have some of those on hand. The part should fit nice and snugly into any bottom corner of the printer - front left or front right is advised though. You will need to alter the wiring so that the Line voltage input to the power supply unit runs through this switch before reaching the power supply's input terminal. If you are not comfortable working on high-voltage electrical wiring, then please find a qualified electrician to help you. High voltage can be deadly!!