HKS 0.7mm Thick Opposed Bead Stopper Type Metal Head Gasket 2013-2021 BRZ / 2013-2016 FRS / 2017-2021 86

Here, you are looking at the HKS Opposed Bead Stopper Type Metal Gasket 2013-2021 BRZ/FRS/86.

t=0.7mm for a Supercharged Engine
The t=0.7mm type utilizes a stopper taller than the t=0.5mm type to provide higher bore seal durability. With stock pistons, the compression ratio is reduced only by 0.1; it allows to maintain high heat efficiency.

Compression Ratio - Stock Thickness: t=0.6mm (ε12.5) HKS Thickness: t=0.7mm (ε12.4)

Maintain a high seal with high pressure!
Both types are endurable against high engine output. Stopper structure of the bore seal is separated type so it prevents leakage even under high gas-pressure at high engine output.

Contact surface pressure is improved!
Special coating was applied on the head side and cylinder side to improve sealing performance when tightening the bolts.

Bore seal pressure was confirmed in figures. (See the diagram below.)