Middle Atlantic Products' SR-SUB Sub-Plate Mounting Kit for 89-D Type Brackets and Electrical Boxes on SR-40-22
Backpan includes all the hardware needed to mount a model SR-40-22
frame to an industry-standard 89-D wall bracket (89-D not included).
If you're using 89-D hardware to secure SR Series racks
or electrical boxes to the wall, you need an SR-SUB kit designed for your model enclosure