Disk body style, 0.021 inches nominal overall height, 0.250 inches nominal overall diameter, 0.028 inches nominal single mounting facility unthreaded mounting hole diameter, 4 unthreaded hole single mounting facility mounting facility type and quantity, four hole - 0.100 inch accommodated device mounting hole pattern style

An item fabricated from electrically nonconductive material specifically designed to provide a support for mounting an electrical and/or an electronic component such as a semiconductor device, relay, or resistor into the next higher assembly. It isolates the component from the mounting surface of the next higher assembly, it may act as a strain relief to avoid damage to the component seal, and it may permit soldering of the component to the next higher assembly without damage. It includes holes, notches, or other provisions for physical alignment and spacing of electrical leads and/or other mounting facilities projecting from the component it mounts. It may also afford protection from shock or vibration. It may be either nonthermally conductive which protects the component from temperature changes in the next higher assembly or it may be thermally conductive which permits heat generated in the component to be drained out to a heat sink. For items whose function is electrical insulation only, see insulator, (as modified). Excludes:holder, (as modified); retainer, (as modified), and spacer, plate.