View bt137s datasheet:

Philips Semiconductors Product specification Triacs BT137S series BT137M series GENERAL DESCRIPTION QUICK REFERENCE DATA Passivated triacs in a plastic SYMBOL PARAMETER MAX. MAX. MAX. UNIT envelope, suitable for surface mounting, intended for use in BT137S (or BT137M)- 500 600 800 applications requiring high BT137S (or BT137M)- 500F 600F 800F bidirectional transient and blocking BT137S (or BT137M)- 500G 600G 800G voltage capability and high thermal VDRM Repetitive peak off-state 500 600 800 V cycling performance. Typical voltages applications include motor control, IT(RMS) RMS on-state current 8 8 8 A industrial and domestic lighting, ITSM Non-repetitive peak on-state 65 65 65 A heating and static switching. current PINNING - SOT428 PIN CONFIGURATION SYMBOL PIN Standard A