This part is a kind of semiconductor called BT134-600.

Function of this product has Triac.

Manufacturers : BLUE ROCKET ELECTRONICS

Image and pinout :

Some of the text within the PDF file :

BT134 Rev.E Mar.-2016 DATA SHEET 描述 / Descriptions TO-220 塑封封装 双向可控硅。Triac in a TO-220 Plastic Package.  特征 / Features 高双向瞬态电压能力和高热循环性能。 high bidirectional transient and blocking voltage capability and high thermal cycling performance. 用途 / Applications 主要用于马达控制，工业和家庭照明灯，加热控制和静电开关。 Typical applications include motor control,industrial and domestic lighting, heating and static switching. 内部等效电路 / Equivalent Circuit 引脚排列 / Pinning 1 23 PIN1：Main Terminal 1 PIN 2：Main Terminal 2 PIN 3：Gate 放大及印章代码 / hFE Classifications & Marking 见印章说明。See Marking Instructions. http://www.fsbrec.com 1/6 BT134 Rev.E Mar.-201 [ ... ]

BT134-600 PDF Datasheet Download