This part is a kind of semiconductor called K2201GL.

Function of this product has Standard Bidirectional SIDAC.

Manufacturers : Littelfuse

Image and pinout :

Some of the text within the PDF file :

Teccor® brand Thyristors Standard Bidirectional SIDACs Kxxx1GL Series RoHS Schematic Symbol Applications Typical application circuit presented in Figure 10 of this data sheet (Typical Metal Halide Ignitor Circuit). Description The Multipulse™ SIDAC is a voltage switch used in MetalHalide lamp ignition circuits, as well as High Pressure Sodium lamp ignition circuits for outdoor street and area lighting. This robust solid-state switch is designed to handle lamp igniter applications requiring operation at ambient temperatures up to 90°C where igniter circuit components can raise SIDAC junction temperature up to 125°C, especially when the lamp element is removed or ruptured. Its excellent csoumitemd ufotartpiornodtuimcieng(tCmOMuMlt)ipmleakpeuslstehsisinroebaucshthparlofdcuycctleboef [ ... ]

K2201GL PDF Datasheet Download