Danchuk Window Regulator Rollers & Rivet installs on the end of the window regulator arms and slide into the window channels. If these parts are missing or cracked, window operation can be difficult or impossible. Replacing these when you have your doors apart will make sure you have perfecly functioning windows. Danchuk #1001 will work on any 1955-1957 Chevy model that uses a 1/4" rivet. Sold each, three required per window; 12 per car. Made in the USA.