This MOR/Ryde Pin Box System uses 100 percent natural rubber shear springs, up to 3 inch fore/aft travel and 1 1/2" side to side travel. It eliminates back and forth chucking and jerking by working on a horizontal plane and provides jerk free starts and stops and an overall smoother ride. This coupler is for the Lippert 1621/1621HD. GVWR of the trailer 11,501 - 14,000