Programmable Unijunction Transistor (UJT) 40V 300 mW 
 
Designed to enable the engineer to “program’’ unijunction characteristics such as RBB, , IV, and IP by merely selecting two resistor values. Application includes thyristor−trigger, oscillator, pulse and timing circuits. These devices may also be used in special thyristor applications due to the availability of an anode gate. Supplied in an inexpensive TO−92 plastic package for high−volume requirements, this package is readily adaptable for use in automatic insertion equipment.
 
Resources: 
1. Datasheet