SZ Free-standing enclosure system, for W: 1200 mm, System Support Rails, Carbon steel, Zinc-plated, 2 system support rails (45 x 25 mm) 4 T-head screws M12 x 60 mm Fasteners, 73269098, 2 pc(s), 11.940 lbs, 4028177099715, For heavy installed equipment such as transformers. T-head screw and slot in the support rail accommodate all mounting dimensions.