COP purifier's two-stage replaceable cartridge combines an ion exchange acid absorbing media to control fluid TAN with high efficiency filtration media to remove solids down to 1 ┬Ám. Three sizes are rated for 900 psig and suit fire-resistant hydraulic fluids and synthetic air compressor oils for continuous bypass, mobile cart-mounted, and kidney loop systems. Fluid Metrics, (770) 393-8636, www.fluidmetrics.com