A complete Lyph-Lock Flask includes a glass top and bottom and a rubber ring. Flasks should be filled no more than one-third of their volume so that maximum surface area is achieved and efficient lyophilization is assured. Adapters are reuqired to attach flasks to freeze dry valve ports (sold separately). Glass flasks and tops withstand max temperature of 490º C. Gaskets withstand a max temperature of 450º C.