Description: This 4-Channel relay module is an automatic switch that uses a small voltage to control a large voltage in an automatic control circuit,playing the role of automatic regulation, safety protection, conversion circuit and so on in the circuit. Features: Equipped with output signal indication. Connect directly to the Micro-controller output port. Equipped with anti-interference and optical isolation. Equipped with diode protection. Response time: less than 20 milliseconds. Long life continuous pull 100,000 times. The external connection using rotating crimp terminals to make wiring more solid. Equipped with fixed mounting holes for easy installation; 4 Channel relay simultaneously control and independent power supply. Specification: Material: Mixture Size: Approx.115 x 90 x 40 mm / 4.53 x 3.54 x 1.57 inch Load: 10A AC250V, 10A DC30V Main Components: EL817SRD-DC5V-SL-C Output Mode: High Level,Low Level Package Includes: 1 Piece 4-Channel Relay Module Note: Please allow a slight difference between the size from the above and the actual item due to manual measurement.