This specification covers the performance requirements for NPN silicon, high-power, 2N5038 and 2N5039 transistors for use in high-speed power-switching applications. Four levels of product assurance (JAN, JANTX, JANTXV and JANS) are provided for each encapsulated device as specified in MIL-PRF-19500/439. Two levels of product assurance (JANHC and JANKC) are provided for each unencapsulated device.