Retractable Captive Panel Fasteners join panels with the proven reliability of a threaded connection. When unfastened, they remain securely attached to the outer panel, preventing lost hardware, and allow quick assembly. They are used (for example) to secure door panels to servers when a loose screw on running equipment could be catastrophic. They are part of the electronics hardware category. They are available in nylon and metal and some are even available color coded (with minimum order quantities).