- Specifications Type: Rubber ball/ steel ball Materials: ABS+Rubber / ABS+Stainless Steel Product Size(L x W x H): 4.5 x 2.8 x 1.4CMPackage Contents: 4pcs Paste Type Universal PulleyProduct type: Casters?Specifications Type: Rubber ball/ steel ball Materials: ABS+Rubber / ABS+Stainless Steel Product Size(L x W x H): 4.5 x 2.8 x 1.4CMPackage Contents: 4pcs Paste Type Universal PulleyProduct type: Casters