The Powermatic 20 in. Extension Bed for PM4224B has cast iron bed mounts that attach to the 4224B lathe, and extend the working distance between centers. The bed extension mounts to predrilled holes in the end of the bed or on the leg. The extension adds 24 in. to the diameter of the work piece when mounted down on the leg and adds 20 in. to working distance between centers.1 year