TS TS punched section with mounting flange, 23 x 73 mm, for inner mounting level: W/D: 500 mm, TS System Chassis 23 x 73 mm, Carbon steel, Zinc-plated, Assembly screws, 73269098, 4 pc(s), 4.594 lbs, 4028177236264, The alternative to the TS 17 x 73 mm system chassis, with punchings for captive nuts/speed nuts instead of slotted holes top and bottom. Simply locate and secure.