Rubber parts last a long time, but not forever. Eventually, after many years of use, rubber tends to stiffen and forms cracks and tears. It's a good thing aFe provides spare parts for their intake systems. This kit is made for aFe Intake Systems 51-10062, 54-10062, & 75-10062, for the 1999-2003 Ford 7.3L Powerstroke engines. It is comprised of two polyurethane 4" couplers, four stainless steel worm-drive hose clamps, one 1/4" x 2" breather hose and clamp, and the trim piece(s) to span the top edge of the heat shield of the intended intake system(s). If your rubber parts are old and worn out, install these replacement parts to prevent dirty air from entering your engine and causing expensive damage.