The HKS MLS Stopper Head Gasket set consists of multiple layers of steel and a special fluorine rubber coating to ensure a good seal on your VQ35 heads to block. A Stopper Ring is molded into the HKS head gasket around the combustion chamber to offer the maximum sealing right around the 350Z and G35 combustion chamber. Bore: up to 97mm VQ Builds VQ35DE Stopper Head Gasket Thickness: 0.7mm Comp Ratio when used on factory motor: 10.3:1