The 8" Ames 2000SS Silver Bullet Series Double Check Valve Assemblies began production in 1998 and are still being produced. They are all stainless steel body devices. Please be sure which model you have as the "SS" and "SE" models use different repair parts. They utilize a single victaulic cover with two self contained plastic cam checks that are held into the body with 4 stainless steel bolts. No special tools are required for servicing.