The #12-24 cage nut kit for strain relief bars is ideal for mounting a variety of rear support bars in square-hole equipment rails found on racks or cabinets. Kit includes a 1" long screw that offers an area where to mount the bar and a hex nut to secure it in place. Includes 100 #12-24 round head 1" screws, 100 #12-24 cage nuts and 100 #12-24 hex nuts.