1、High-level trigger: In industrial control, called PNP trigger, positive trigger, that is, the relay closes when the trigger voltage reaches the trigger condition before the trigger terminal and the negative pole of the power supply. 2、Stable performance of electronic components, so that your equipment can work stably. 3、High sensitivity of this product. 4、The use of the product expansion capability, can be used for all types of DIY. 5、Equipped with fuse to ensure the safe use of this module. Feature: High-level trigger: In industrial control, called PNP trigger, positive trigger, that is, the relay closes when the trigger voltage reaches the trigger condition before the trigger terminal and the negative pole of the power supply. Stable performance of electronic components, so that your equipment can work stably. High sensitivity of this product. The use of the product expansion capability, can be used for all types of DIY. Equipped with fuse to ensure the safe use of this module. Specification: Type: 8 Channel Rated current: 2A Rated voltage: 5V Weight: 70g / 2.5oz Package list: 1 * Relay Module Note: The actual product color may deviate from the photo due to light. There may be a slight deviation in the measurement of product. 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.