Dual 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 can’t understand why you’d want to use them). Pull as hard as you can, foam will rip before the glued seam will

Light color foam easier to spot where the filter oil has covered and where it has not

OEM size for more dirt stopping capability

Handmade

Every square inch of each filter is and inspected for quality

One year warranty

Made in the USA, not a cheap Chinese throw away