Caster; Rigid; 8 x 3; Heavy Duty PolyU on Cast (Gr/Blk); Top Plate (6-1/4x7-1/2: holes: 4-1/8x6 slotted to 4-1/2x6-1/8; 1/2 bolt); Zinc; Roller Brng; 3500# (Item #66597)