Product Description 31mm OD. 3.50mm shim. 25mm skirt. Kelford Cams DLC Coated Buckets Feature: Larger internal fillet and reinforced skirt. Increased rigidity increases both camshaft and bucket longevity. DLC coated follower surface decrease friction Decreases surface wear and oil temps Improves torque required to turn the camshaft. Available in 2.78mm, 3.0mm, 3.50mm, 3.78mm, 5.25mm, 6.15mm & 6.40mm ‘shim’ thickness