316 Stainless Steel wetted parts.5" 304SS Case, 316SS Internals, 5000 psi, 1/4 NPT Male Bottom Conn, Glycerin Filled, Safety Glass Lens Cleaning for Oxygen Service O2 is available only for dry or HL Halocarbon filled gauges. Vacuum and compound ranges through 0 psi to 20,000 psi..