Flexible, non-contaminating silicone rubber top fits on Fast-Freeze 120, 150 and 300 ml bottoms. Fast-Freeze Flasks attach with adapters to valve ports on Labconco Drying Chambers and Manifolds. A complete Fast-Freeze Flask consists a rubber top, glass bottom and a supply of filter paper. Tops, bottoms and filter paper are available separately as replacement components. Adapters are available in borosilicate glass or stainless steel. Fast-Freeze Flasks and Adapters are compatible with any brand freeze dryer that has 1/2" or 3/4" diameter valve ports. Glass flasks withstand max temperature of 490º C. Flask toppers withstand a max temperature of 450º C.