Thyristor applications, Silicon controlled rectifier, What is a Protection Thyristor

 BTA16 Series 600 Vdrm 16 A Flange Mount Snubberless Triac Thyristor - TO-220AB

https://www.futureelectronics.com/p/electromechanical--circuit-protection--protection-thyristors/bta16-600bwrg-stmicroelectronics-5949201