The X21L One-Liter Stabilizer air sampling canisters are fabricated from carefully inspected 304L stainless steel. The low carbon 304L grade of stainless steel makes it possible to achieve the highest integrity welds by minimizing the problems associated with carbide precipitation. All canister body welds are also fully penetrated while purged with a continuous blanket of ultrapure argon. The resulting oxidation-free and particle-free surface alleviates the potential for unswept surface areas and the entrapment of contaminants.