Stmicroelectronics T835T-8T.
TRIAC, 8A, 800V, TO-220AB-3; Peak Repetitive Off-State Voltage, Vdrm:800V; On State RMS Current IT(rms):8A; Triac Case Style:TO-220AB; Gate Trigger Current Max (QI), Igt:35mA; Gate Trigger Voltage Max Vgt:1.3V; Peak Gate Power:1W