Designed to be used in relay and grid-controlled rectifier applications. New old stock * New In Box * No longer available for export. MFR: RCA, Westinghouse, Sylvania, GE, Tung Sol, National SKU: 2D21
Designed for use in the power output stage of compact, battery operated equipment. New old stock * New In Box * No longer available for export. MFR: RCA, Zenith, Sylvania, Raytheon, Philco, Akrad, Westinghouse SKU: 3V4