Putoline air filters, based on leading-edge open-cell foam technology, bring users major benefits, including: Improved performance through increased airflow Improved protection through finer filtration levels Substantial cost savings through serviceability and re-use Fully reticulated (open cell) foam, as used in all Putoline filter products, consists of a honeycomb of tiny, interlocking cells of uniform size. When treated with specially formulated filter oil, each passageway is like hundreds of very small centrifugal/oil bath filters connected one to another. In this way, the foam traps and holds the particles throughout the entire volume of foam. The development of this unique foam represents a major advancement in air filtration technology. As a result, foam air filters, when compared with paper or cotton gauze equivalents, combine great airflow capability, huge dust holding capacity, and very high filtration efficiency for even extremely small particles. Construction: Coarse open-pore foam catches airborne dirt, grime and sand. Fine open-pore inner foam acts as a second filter to trap the smallest particles while ensuring maximum air passage. Exclusively formulated adhesive ensures glue seams will not break down. Thick, flat foam, greaseless sealing ring ensures maximum contact with your airbox, while acting as a breathable gasket for increased air passage. Fused outer and inner elements prevent dirt and grime from being lodged between layers. Trapped particles can restrict airflow. If dirt works it's way into your engine, a pinhead-sized granule will gouge your piston and rings like a bullet.
