The BT137-600E is a triac sensitive gate with a TO220 package. It is designed for use in AC switching applications and has a maximum current rating of 8A and a maximum voltage rating of 600V. Triacs are three-terminal semiconductor devices that control the flow of AC current and are commonly used in applications such as light dimming, motor speed control, and heating control. The "sensitive gate" designation indicates that the triac has a lower trigger current, which makes it easier to trigger compared to a standard triac.

Passivated, sensitive gate triacs in a plastic envelope, intended for use in general purpose bidirectional switching and phase control applications, where high sensitivity is required in all four quadrants.