Part# S12S40SU90BLF23XX SPECS Fork Type: Stainless Swivel Wheel Diameter: 4" Wheel Tread Width: 1-1/4" Wheel Type: Solid Polyurethane  Wheel Durometer: Shore D 60 (+/-5) Bearing Type: None/ Plain/Bore Fastening Type: Top Plate Top Plate Size: 2-3/8" x 3-5/8" Bolt Hole Spacing: 1-3/4" x 3" Bolt Hole Size: 5/16" Temp Range: -50° to 180° F Brake Type: None