COMP Cams Tool Steel Solid/Mechanical Lifters are made from durable M2-grade Tool Steel that is lightweight, yet it is as strong as regular steel lifters. These Tool Steel Lifters are offered in three different diameters that are available in a coated, non-coated and non-coated EDM (Oiling Hole) version. The DLC (Diamond Like Carbon), multi-layer coating that is extremely slick and hard, and resistant to abrasive wear in extreme environments. This wear resistance requires less power to run valve train and lowers friction, heat and oil temps. COMP Cams Tool Steel Solid/Mechanical Lifters are compatible with most camshaft materials.