For Higher Frequency Applications ( more than 50-60Hz ) Inverter Thyristors with Lower Values of Turn Off Time (Tq) are used. They have optimized Turn Off Parameters. Typical Application is Induction Furnaces both Hardening and Melting. It comes in both Stud Base and Disc Types. Lower Tq like 10 Microseconds also available. Distributed gate Parameters are the best for optimized performance.