FOAM AIR FILTERS: NO TOIL manufactures the world's best 2-stage foam airfilters. Using only the best flame-laminated dual-layer foam bonded withthe highest quality glue, they hand make each foam filter to stand up tothe roughest & toughest riding or terrain. NO TOIL filters can be used withNO TOIL biodegradable "clean in water" cleaner, providing the best airfiltration system in the world.