Allstar 3/8 inch Engine Rocker Arm Stud Girdle Nut Kit for Allstar Pack of 16) features an engine rocker arm stud girdle nut kit. It fits small block Chevy applications using 3/8 inch rocker arm studs. It is designed to work with Allstar stud girdles and also many other popular brands. It is sold as one set of 16 pieces and is backed by a 90-day limited factory warranty.