This is a front roller set for the Hydra PRO AMS that requires no permanent modification to your existing front rollers and no parts you don't already have.
I used Bambu PETG-CF for the shafts/gears and SpiderFlex 75a Matte TPE for the roller pads. Normal PETG works fine for the shafts/gears, and PLA would presumably be fine as well. I would recommend using softer a TPU or even TPE for the roller pads if possible, alternatively you could print them in something that isn't grippy and apply some duct tape or electrical tape later. When using too hard of a material for the roller pads you may notice some roller slippage.
All parts are friction fit so they are very tight. I would recommend having a small mallet and some glue handy, though neither are strictly required.