Feature: 1. With power and relay action instructions, the suction is bright and the disconnection is not bright. When there is a signal at the signal input terminal, the common terminal and the normally open terminal will be connected 2. Can be used as a microcontroller development board or PLC module, can be used as home appliance control 3. Control DC or AC signal, the maximum can control 250V AC and 30V DC load 4. Single pole double throw, blue KF301 terminal is more convenient to connect control line 5. Adopted of high quality electronic components, and accuracy process, ensure for the durability Specification: Item Type: Relay ModuleDescription: Low level: 3V Control DC or AC signal, can control the maximum 250V AC and 30V DC load. Single pole double throw Size: Approx. 74 x 44mm / 2.9 x 1.7in Notes on the Trigger Mode of High Level and Low Level: High-level trigger refers to the voltage trigger mode between the signal input terminal and the ground, which can be understood as a method of triggering the signal input terminal and the VCC positive short circuit; Low-level triggering refers to the trigger mode in which the voltage between the signal input terminal and ground is OV, which can be understood as a way to trigger the short-circuit between the signal input terminal and GND negative electrode. Package List: 1 x Relay Module