If you have a product that needs the structure and durability of a steel drum yet the compatibility of polyethylene, the Composite Drum is your tool. It meeds UN 6HA1 Standards. The Closed Head Drum has a 40 mil polyethylene liner that is non removable inserted inside the steel outer drum. The Open Head Drum also has a 40 mil tight head liner that can be removed and replaced so you can reuse your drum. It has a 12 gauge locking ring, bolt and nut and a gasketed cover. Cover has a 2" Trisure NPS fitting adn 2" Trisure NPS with 3/4" NPS combo fitting.