SBI Super-Premium "Star Series" Nickel Based Non-Magnetic Valve Seat Inserts are designed specifically for engines operating in extreme high heat conditions and/or using gaseous fuels such as CNG or LPG. Due to varying circumstances, these types of applications or operating conditions require a valve seat insert material that offers excellent wear and very high hot hardness characteristics. The "Star Series" insert was developed to retain hardness beyond 1600° F to combat these high temperature conditions and prevent exhaust valve seat erosion (recession) for greater service life.