This is a set of 6 Haltec GL-2928 M22-1.5 two-piece flange wheel nuts with a 28mm sleeve and a 33mm hex for uni-mount hub pilot 10 hole wheel systems found on semi trucks. Skirt nuts prevent rims from clocking (shifting forward or backwards) by filling the extra space between the stud and stud hole. This helps to improve vehicle stopping power . reduces vibration and increases the life of the wheel. This 28mm sleeve nut is designed for use on heavy duty aluminum wheels in the steer position . aluminum Super Single Wide Base wheels in the steer or drive position and aluminum outer . steel inner dual wheel applications in the drive position. Haltec has been the leader in valve systems and wheel components for over 45 years.