4 in. Rubber Swivel Caster

Elastic Blue soft rubber swivel caster for general use. Instantly returns to original shape after relieved of load. Smooth rolling mechanism for easy movement on a variety of surfaces (carpet, ceramic, wood, and concrete) and for passing over small obstacles. Abrasion-resistant and does not mark surfaces. Assembly with 3 1/8 in. x 4 in. screw-on plate, blue.