Surge Protector plug, thyristor surge protection, Triac thyristor circuits

 BTA16 Series 800 Vdrm 16 A Flange Mount Standard Triac Thyristor - TO-220AB

https://www.futureelectronics.com/p/electromechanical--circuit-protection--power-thyristors/bta16-800brg-stmicroelectronics-2124373