PanelFast makes these Quarter Turn, Quick Release, Self -eject fasteners right here in the USA>
The self eject fastener is designed to capture the quarter turn button within its mounting plate to eliminate loss of the button and allow for quicker panel installation.Each assembly has small spring under the head of the button to eject it from the locking position when it is turned.
They are available in several stud diameters and grip lengths as well as different head styles to meet your needs.
5/16" Winged Self-Eject Steel These PanelFast Winged Self Eject Fasteners are designed with a 5/16" stud diameter and a microwelded wing tab for easy locking and unlocking. Part Number: EW5400 Price: $3.91 $3.08
7/16" Allen Self Eject, Aluminum Large diameter, aluminum, Allen Head, self eject fastener Part Number: PANBEA6400 Price: $3.30 $2.49