CATALINA 22 CU FT HELIUM CYLINDER TANK WITH CGA 580 VALVE USED FOR NITROGEN, HELIUM, ARGON SHIPPED EMPTY Specification: DOT-3AL & TC-3ALM designed; ISO design cylinders are available Finish: Standard finish is brushed body with unpainted crown; Alloy: Manufactured from high strength aluminum alloy 6061-T6; CGA-580 Threads: Standard thread is .750-16 UNF & 1.125-12 UNF - Taper threads are 3/4-14 NGT, 25E Our aluminum helium cylinders 40% lighter than steel cylinders