1、High-level trigger: In industrial control, called PNP trigger, negetive trigger, when the voltage between the trigger terminal and the negative pole of the power supply is 0V or close to 0V. 2、Stable performance of electronic components, so that your equipment can work stably. 3、High sensitivity of products. 4、The use of the product expansion capability, can be used for all types of DIY. 5、With fuse to ensure the safe use of this module. Features: High-level trigger: In industrial control, called PNP trigger, negetive trigger, when the voltage between the trigger terminal and the negative pole of the power supply is 0V or close to 0V. Stable performance of electronic components, so that your equipment can work stably. High sensitivity of products. The use of the product expansion capability, can be used for all types of DIY. With fuse to ensure the safe use of this module. Specification: Type: 1 Channel Weight: Approx.12g/ 0.4oz Rated current: 2A Voltage: DC 5V/12V (Optional) Package List: 1 * SSR Module Note: DC +: positive power supply DC-: connect power negative The CH terminal is the trigger terminal of the module. When there is a trigger signal, the output switches (A, B) of the solid state relay will close. The load will be conductive.