Cometic MLS (Multi-Layer Steel) head gaskets are made of 3 layers of stainless steel. Cometic uses stainless steel for increased strength, ability to rebound, and resistance to corrosion. The outer layers are coated with Viton and beaded for perfect embossment. Viton is a fluoroelastomer rubber-based material that can withstand 482°F and able to seal the most harsh environments such as high load conditions and different surface finishings. The center layer is uncoated which can be varied to accommodate multiple thicknesses.