COMETIC MLX (Multi-Layer Stopper) gaskets utilize an integrated stopper layer for combustion chamber sealing and improved clamp load around the cylinder without increasing bore distortion. MLX technology can be found in some head gaskets and are made from the same materials as our MLS Head Gaskets. No sealants or re-torque required. BMW N54B30 .044" MLX Cylinder Head Gasket, 85mm Bore. BMW N54B30