This part is a kind of semiconductor called CL01-12S.

Function of this product has Plastic High Voltage Rectifier.

Manufacturers : SIYU

Image and pinout :

Some of the text within the PDF file :

www.DataSheet.co.kr SIYU R 塑封高压二极管 反向电压 12KV 正向电流 350m A 特征 Features · IF(AV)　 ·VRRM 15±0.2 4.5±0.2 CL01-12S Plastic High Voltage Rectifier Reverse Voltage 12KV Forward Current 350mA 1.2±0.03 24 MIN 　350 mA 12KV High reliability ·高可靠性 24 MIN 用途 Purpose Unit：mm ·微波炉及其他电子设备高压电源整流用 　Rectification for high voltage power supply of magnetron in Micro wave owen and others 极限值和温度特性 TA = 25℃ 除非另有规定。 Maximum Ratings & Thermal Characteristics 参数名称 Item 反向重复峰值电压 Repetitive Peak Reverse Voltage 正向平均电流 Average Forward Current 正向（不重复）浪涌电流 Non-Repetitive Forward Surge Current 工作环境温度 Ambient Tempe [ ... ]

CL01-12S PDF Datasheet Download