ALEKO Gate Part #4 Rear Nylon Wheel Guide Roller for Chain Link Fence Gate Fits 2-3/8 Inch Pipe Track 4 Inch U-Grove Bolt Most commonly used wheel for chain link gates and fence frames Will work perfect for commercial or residential use, compatible with many gates and fences. Fast and easy installation with affordable price Wheel Material: Nylon. Part Material: Steel. Finish: Galvanized. Dimensions: Please see Picture. Fits: 2-3/8 inch pipe tracks and more. Wheel diameter is 6 1/4 inches. 4 Inch u-groove bolt.