McMaster 30305T542 Samson Caster with 4 1 2" x 4" Mounting Plate, Swivel with Total Lock and 4" Diameter Phenolic Wheel 804JY0 ASTM B88 Pipe Fitting Connection ASTM B88 Pipe Fitting Connection Type Press x Female Pipe Thread Temp Footwear Closure Type Pull On They have nonmarking phenolic wheels that roll best on smooth surfaces Oil Fabrication Stamped Material Zinc Plated Steel Mount Type Plate Mounting Fasteners Included No Center to Center Length (A) 3 5 8" Center to Center Length (B) 3" Center to Center Width (A) 3" Center to Center Width (B) 2 5 8" Length 4 1 2" Width 4" Type Ball Seal Type Open Construction Dual Raceway Swivel Lock Activation Foot Pedal Tread Style Flat Wheel Tread Material Phenolic Country of Origin United States DFARS Compliance Specialty Metals COTS Exempt Export Control Classification Number (ECCN) EAR99 REACH Compliance Not Compliant RoHS Compliance RoHS 3 (2015 863 EU) Compliant Schedule B Number 871690