This kit is a reproduction of the MCR board mounting bracket set for Bally Midway's MCR games such as Tron, Tapper, Spy Hunter, Kick-Man, Satan's Hollow and Discs of Tron (among others). This is the bracket set that goes above and below the PCB stack and holds it in place. 

Please note, board stacks with metal plates will require either modification of the bottom piece or they will sit at 5-10 degrees of tilt.

These come complete with sticker courtesy of Rich and Kendra at thisoldgame.com