The COAX Depth Filter cartridge is an integral two stage depth filter. The first stage is made of nonwoven melt blown polypropylene to trap coarser particles. The second stage is composed of a bicomponent polypropylene and polyethylene fiber to provide fine particle retention. This unique design provides a true graded, two zone structure that offers a marked increase in useful life and dirt capacity. In addition, the rigid nature means there is no flexing of the cartridge and greatly reducing media migration and particle unloading.