NO-TOIL FILTER BETADual stage foam: Two different pore sizes create more trapping area for even the smallest dust particles Flame laminated foam: Both stages are not glued, but heat sealed to provide maximum air flow Reticulated foam: Increases dirt stopping surface area and increase foam strength Strongest glue seams will withstand harsh solvents and gas (although we cant understand why youd want to use them). Pull as hard as you can, foam will rip before the glued