4 Rigid - 4 Swiwel - 4 SB (4 Swivel with Brake) - 2R + 2S (2 Rigid + 2 Swivel) - 2R + 2SB (2 Ridid + 2 Swivel with Brake) - 2S + 2SB (2 Swivel + 2 Swivel with Brake). Top plate : 3-15/16" x 4-1/2". 6"x2" - 4 Caster Set - 4 Rigid - 4 Swiwel - 4 SB (4 Swivel with Brake) - 2R + 2S (2 Rigid + 2 Swivel) - 2R + 2SB (2 Ridid + 2 Swivel with Brake) - 2S + 2SB (2 Swivel + 2 Swivel with Brake) Description 1. Top plate : 3-15/16" x 4-1/2" 2. Load Capacity : 750 lbs/ea 5.