The NTE5400 through NTE5406 sensitive gate SCR semiconductors are halfwave unidirectional gate controlled rectifiers (SCR−thyristor) rated at 0.8 amps RMS maximum on−state current, with rated voltages up to 600 volts.
These devices feature 200 microamp gate sensitivity, 5 millamp holding current and 8 amp surge capabilities.
Available in a TO92 plastic package, these devices feature excellent environmental stress and temperature cycling characteristics and, coupled with their small size and electrical performance, lend themselves to various types of control functions encountered with sensors, motors, lamps, relays, counters, triggers, etc.
 
Full spec sheet:
https://www.nteinc.com/specs/5400to5499/pdf/nte5400_06.pdf