These "push-nut" mid-panel fasteners feature a spring member in the center of the upper leg, offering wide panel ranges. They eliminate the need for two close-tolerance leaf springs and improve cycle life and effective spring action. Spring nuts are one-piece, self-locking, multi-purpose devices that prevent screws from loosening due to vibration. The use of push nuts can eliminate the need for additional fasteners. And, because they allow faster and easier assembly, push nuts can lower manufacturing cost - requiring no special tools, equipment or skills for installation.