Mine came with Uni Foam pods filters but over the years the foam deteriorated and only the springs and end caps remained. The Dynojet stage 3 kit paperwork mentions to use K&N filters with a 4 into 1 pipe. I was going to give them a go but the price for them was just too steep!Yeah, somebody stuck those (not so good) K&N's on mine too when I got it. They were the first things to go for my restoration. Have a newish set of 4 if you want them.