COMETIC head gaskets for BMW M3 E46 6 Cyl 3.2 Those head gaskets are made of 3 layers of stainless steel. The elastomer outer layer increases oil and heat resistance (up to 250°C!). Multiple thicknesses available. Ideal for use with aluminium or cast iron. Their unique composition is perfectly resistant to shearing no need to tighten the head gaskets. Characteristics : bore : 87.50 thickness : 0.69 mm