Constructed of non-metallic materials. Filtraters quickly and simply, 3 times faster than the gravity method. Filtrate is collected directly in a beaker, eliminating transfers. Filter domes are constructed of borosilicate glass and polypropylene. Chances of trace metal contamination are virtually eliminated. Designed for direct filtration and for use where transfers should be avoided. Filter domes are recommended for EPA-type sample digestions prior to Atomic Absorption Spectroscopy. Several units may be connected in a series and vacuum applied from a single source. The upper portion of the dome is tooled to accept a No. 8 stopper and the popular 47 and 90 mm funnel/support filtration assemblies. Valve and hose connections are made of CTFE. O-rings are Viton.