Product Info: - Part: Idler Pulley - Material: Steel - Belt Type: Serpentine - Color: Black - Mount Hole Diameter: 0.669 inches - Mount Hole Diameter: 17 millimeters - Mount Hole Quantity: 1 - Pulley Center Bore Diameter: 0.669 inches - Pulley Center Bore Diameter: 17 millimeters - Pulley Outside Diameter: 3.