Uxcell a15082600ux0445 Computer Chairs 8mm Thread Stem 1.5 Inch Diameter Swivel Caster Wheel 4pcs (Pack of 4) Main Material: Rubber, Metal; Package Content: 4 x Stem Caster Wheel Product Name: Stem Caster Wheel; Weight: 613g Features: Swivel; Main Color: Black, Silver Tone