Complete fast-freeze flask with snap-on rubber cap and 1/2-inch or 3/4-inch O.D. plain or valve adapter, compatible with all major brand freeze drying manifold valves. Borosilicate flasks are designed for ease of handling, faster loading. Uniform wall weight maximizes heat transfer while maintaining structural strength. Wide (53mm ID) mouth provides easy access to inner walls. Snap-on black rubber cap is grease free; one size fits all capacity flasks. Plain straight adapter for connecting flask cap to lyophilizer manifold is removable and fabricated from PTFE. PTFE adapter also available with shut-off valve. Complete item consists of flask, cap and PTFE adapter.