The special class of micro-glass and other fibers used in Z media are manufactured with utmost precision, to specific thicknesses and densities, and bonded with select resins to create material with extra fine passages. No other filter media can provide the benefits of Schroeder's Excellement Z media: maximum dirt-holding capacity, superior particle capture, excellent beta stability, minimum pressure drop, high flow rate and low operating cost. The typical multiple layer construction has evolved from comprehensive laboratory testing to provide extended element life and system protection. Each successive layer performs a distinct and necessary function. The outermost layer is designed to maintain element integrity. Beyond this layer is a spun bonded scrim, offering coarse filtration and protection for the filtering layers within. Multiple Schroeder CCZ10 Filter Cartridge for DF40, Z-Media: Micro-Glass, 9.5" Cartridge Height, 3.0" Cartridge OD, 1.1" Cartridge ID; 10 Micron (absolute); Removes: Rust, Metallic Debris, Fibers, Dirt.