These Push Type Retainers are made of high-strength plastic, these snap-in retainers are designed to resist corrosion, while their 'push lock' mechanism makes them a snap to install and remove. Perfect for attaching car door panels, fender liners, grills, or bumpers to frames, these retainers are perfect for day-to-day automotive maintenance duties. 11146B Head Diameter : 5/16" Stem Length : 13/16" Hole Size : 1/4"