Ideal for small samples. Top section is clear to allow observation from any angle. Stopcock allows gentle air entrance when releasing vacuum. A peripheral flange around the bottom section fits into two snap locks, sealing the two halves against a Buna-N O-ring. Top section is molded polycarbonate with polypropylene stopcock with 2mm bore Teflon* TFE resin plug; the bottom section is polypropylene. Vacuum retention rating is 740mm Hg (29in. Hg). (Bel-Art F410990000)