Replace the existing plate diaphragms on your Walthers Proto car with this part so your cars match the prototype cars as they exist today. Each kit includes a pair of replacement diaphragms, enough to complete one car. Just remove the existing factory diaphragm, then glue the new part in place. The tubing is flexible just like the prototype. When running cars with these diaphragms on layouts with curves less than 26” radius, you may need to replace the factory coupler with one that uses a longer shank.