Guys I thought I would service my air compressor by adding little oil,drain tank.So I thought while here I would dust off the air filter.Well heck it’s gone just little dust from that old sponge filter.Guts these filters are made out of just a very porous sponge filter.So I went shopping found what I needed but they want 38.00 ouch.Its just maybe 2”x3”x6” So surely there material out there that I can make my own but when I google air filter all kinds choices come up but not what I’m looking for.I don't know what you would call this piece of sponge but surely there something out there thats cheaper than 38.00 Guys what could suggest for material for making your own?