This part is a kind of semiconductor called BTB04.

Function of this product has Triac.

Manufacturers : CDIL

Image and pinout :

Some of the text within the PDF file :

Continental Device India Limited An ISO/TS 16949, ISO 9001 and ISO 14001 Certified Company BTA04/BTB04 Triac Series TO-220 Absolute maximum ratings Parameter peak repetitive off-stage voltage on-state RMS current NON repetitive surge peak on-state current critical rate of rise on-state current peak gate current average gate power dissipation storage temperature range operating junction temperature range Symbol VDRM, VRRM IT(RMS) ITSM dI/dt (Q1-3) IGM PG(AV) Tstg Tj Value 600 4 35 50 4 0.5 -40 to +150 125 Unit V A A A/µs A W oC oC Test condition Tc<105 oC Tp=20ms, Tj=25 ºC, F=50HZ Electrical characteristics ( Tj=25ºC) unless otherwise specified Parameter Symbol gate trigger current IGT gate trigger voltage hold current critical rate of rise off-state voltage on-state voltage [ ... ]

BTB04 PDF Datasheet Download