Model# 6438 JCM 6438 All 316 Stainless Steel Tap Slv with Threaded Outlet. DescriptionAll 316 Stainless Steel Tap Sleeve with Threaded Outlet Model# 6439 JCM 6439 All 316 Stainless Steel Tap Sleeve with MJ Outlet. DescriptionAll 316 Stainless Steel Tapping Sleeve with Mechanical Joint Outlet. For corrosive or acidic environments.