2" Copper Tri-Clamp step ferrules fit on the outside of the copper pipe that you are attaching them to and because they fit on the OD they will fit any type of copper M, L, K, & DWV. No sanding, grinding, hammering, or cussing needed as they just plain fit perfect. These are made to our specifications and are laser branded www.hiproofproducts.com You wont find a better ferrule available anywhere, this is the best!