Vessels feature a lockable necktube insert that maintains thermal performance. High strength, aluminum shell assures durability. Thermal barrier, advanced insulation and vacuum yield optimum thermal efficiency. Vapor shippers are built with material that absorbs liquid nitrogen and leaves only the vapor phase. Shippers have slotted and numbered indexing ring and strong necktubes; they make outstanding biological shippers. Include 1 storage canister. 6 liters capacity. Static hold time: 26 days. Evaporation rate: 0.23 liters/ per day. 3.75" Necktube diameter. 11.25" Outside diameter. 20.125" Overall height. Empty weight: 15 lbs. Full weight: 25 lbs. 11" Canister length. 2.96" Canister inside diameter.