An item designed to electrically connect and mechanically position the base of an item having plug-in-type contacts, and to facilitate replacement of the item accommodated. It includes sockets which accommodate the contacts of capacitors, coils, crystals, electron tubes, relays, semiconductor devices and vibrators. Excludes sockets or receptacles designed to accommodate plug-in component circuit boards (printed circuit boards) and electronic modules or sub-assemblies. Also excludes heat-dissipating (not heat-sinks) sockets for mounting power transistors".