The "VH" series of resistors is the hermetic version of several molded "S" series devices. Hermetic sealing eliminates the ingress of both oxygen, which degrades resistors over long periods, and moisture which degrades resistors more quickly. These parts are made with glass to metal seal enclosures employing Kovar eyelets which allow the copper leads to pass through the enclosure to minimize the thermal EMF from the lead junctions. Rubber fill between the metal housing and resistance element acts both as a mechanical damper and thermal transfer path. VHS102 and VH102K are the hermetically-sealed counterpart of the S102C and S102K high-performance molded resistors. VHS555 is the hermetically-sealed version of the S555, MIL style RNC90Y.