Medium Duty Swivel Expanding Stem Caster with Brake - Wheel Diameter: 5" (127mm) - Load Height: 6" (152mm) - For 1-1/2" Tubing - Square or Round. - Swivel Radius: 4" (101mm) - Wheel Type: Black Polyolefin - Load Capacity: 250lbs (110Kg) - Adapts to either Round or Square Tubing. Caster expands to fit 16, 18 and 20 (1.5mm, 1.2mm and 1mm) gauge wall thickness tubing. - Full 1-1/4" (32mm) tread width. NSF Approved. Also fits 1-1/4" PIPE.