This is one of the scr types.
Part Number: PCR406J
Function: 400V, 0.8A, SCR ( Silicon Controll Rectifier )
Package: TO-92 Type
Manufacturer: SLT, Unisonic
See the preview image and the PDF file for more information.
Silicon controlled rectifiers are high performance planner diffused PNPN devices.
These parts are intended for low cost high volume applications.
This features is High Blocking Voltage,High Surge Current Capability.
Applied to high Voltage control circuit.
PCR406J Pinout :