Replace your leaky or blown head gasket with this high - quality Sinister Diesel Duramax head gasket. It's a direct replacement for the OE head gasket, but features an extra - durable design which handles the extreme pressure and heat of a turbo diesel engine without problems. This will fit Duramax engines LB7, LLY, LBZ, and LMM from 2001 to 2010., Each Sinister Black Diamond Head Gasket is made of 5 layers of stainless steel sandwiched together. The design provides a heavy - duty seal for each cylinder, while an adaptive fluoroelastomer (FKM) coating provides an optimal seal for fluids. That means a secure, super tight seal between the cylinder block and cylinder head, ensuring proper operation of your engine., Features Construction - Multi - layer Steel, Product Design - Driver Side, Grade B 1.00mm thickness, Coated with Adaptive fluoroelastomer (FKM), Kit Includes - (1) Sinister Diesel Black Diamond 20mm Head Gasket