The 4.5 Liter Air Sampling Canister features 304L Stainless Steel which is electro-polished inside and out. Designed to support global atmospheric research programs, the canister includes an ultra-clean valve which is protected by the carrying handle to ensure sample integrity. Both the valve and canister have an all-metal construction. The self-standing design provides more stability in use. The 4.5 Liter Air Sampling Canister has an operating pressure of 300 PSIG and is certified to DOT 4D.