Venefilter Inc., this filter has a construction which is made from acrylic fibers / phenolic resin, which produces an extremely rigid pores. This construction allows the filter holder of viscosity and temperature extremes without compression or collapse conditions. It also has a true graded density construction that allows full use of the depth of the filter, placing coarse particles captured on the outer areas and the finest particles closer to the core. VFPR1Features VFPR1 Build a rigid acrylic fiber / phenolic resin, which prevents the discharge even at high differential pressures. Corrugated outer surface, which increases the surface area for a longer life. Available in a wide range of particle removal efficiencies from 1 to 100 microns. Available with optional final configurations, for installation in most cases. Core contains metal or plastic, to facilitate removal. Wide chemical compatibility.