These CNC-machined polymer buffer pins replace the large metal buffer pin at the back of your KC-02 receiver. They make the sound of your bolt recoil much quieter, but most importantly, they help reduce the wear and tear on your bolt carrier, which is especially important if you have a RogueWorx aluminium bolt carrier.
A polymer buffer pin is a standard upgrade used on real steel Ruger 10/22's for the same reason.
IMPORTANT NOTE: These pins will get squashed flat by the action of the bolt hitting them. Don't panic, this is supposed to happen. Once it's deformed fully into the right shape to suit your bolt, you won't be able to remove this pin without damaging it so be aware of that. THEY ARE SUPPOSED TO GET SQUASHED. If they didn't squash down, they would not be any better than the existing steel pin. If you are concerned about having to replace your buffer pin in future, buy more than 1.