LOHOME&reg; Caster Wheel, Pack of 4 PCS 1.5" Dual Wheel Swivel Caster Square Top Plate Rotary Caster Office Chair Replacement Type: Rotatable, Dual Wheel, Square Top Plate; Material : Nylon, Metal. Dual wheels for easier rolling on carpet; half-cover helps keep wheels clear. Screw Hole Distance(Approx.) : 2.5cm / 1" (Centre to Centre). Hole Dia (Each): 4mm / 0.16" Wheel Size: 39 x 12mm / 1.5" x 0.47" (D*T). Top Plate Size: 3.4x 3.4 x 0.1cm / 1.3" x 1.3" x 0.04"(L*W*T); Overall Size: 5.5x 5x 4cm / 2.2" x 2" x 1.6"(L*W*H). Used widely for the furniture, hand trolley, shopping cart, appliances equipments and kinds of industrial equipments.