The heavy duty cutter wheel attaches to the frame assembly and helps to make cuts in pipes. It is sold individually and is a genuine OEM sourced part which is specially designed for use with Ridgid tubing cutters. The cutter wheel is made out of metal and will require replacing if it breaks.
This is a replacement lock ring is specially made for use with Dynabrade power tools. It is designed to create a seal between two connected parts. Over time o-rings will become brittle allowing for air leaks. Because of this rings should be inspected periodically. If parts are showing signs of wear they should be replaced. This is a rubber o-ring and it is sold individually.