This is 3 pieces of 5V 1-channel relay modules that work with Arduino, ESP32, ESP8266, Raspberry Pi, or any 5V or 3.3V microcontroller. A single package includes 3 pieces of relay modules. SPECIFICATION: - Normally open and normally closed. - High-level trigger or low-Level trigger selection by a jumper. - Optocoupler isolation. - Terminal blocks for both input and output. - Two LED indicators: power (green LED), the relay status (red LED). - Fault-tolerant design, even if the control line is broken, the relay will not operate. - Operating voltage (power): 5V. - Trigger voltage: 3.3V to 5V. - Trigger current: 5mA. - Maximum load: AC 250V/10A, DC 30V/10A - Dimension: 50mm x 26mm x 18.5mm (L x W x H). INPUT INTERFACE: - DC+ : Connect the positive pole of the 5V power supply. - DC- : Connected the negative pole of the 5V power supply. - IN: Signal trigger input (3.3V to 5V, high or low level signal selected via a jumper). OUTPUT INTERFACE: - NO: The normally open interface. - NC: The normally closed interface. - COM: The common interface for both normally open and normally closed. High/low level trigger selection jumper: - If the jumper is placed between COM and L, the relay uses LOW level trigger. - If the jumper is placed between COM and H, the relay uses HIGH level trigger. HOW IT WORKS: High Level Trigger: - When IN is LOW level signal, the NO does not connect with COM and the NC connects with COM. - When IN is HIGH level signal, the NO connects with COM and the NC does not connect with COM. Low Level Trigger: - When IN is LOW level signal, the NO connects with COM and the NC does not connect with COM. - When IN is HIGH level signal, the NO does not connect with COM and the NC connects with COM. TUTORIALS: - Arduino and ESP32 online tutorials: DIYables Relay

Relay with two LED Indicators: power (green LED), the relay status (red LED). Relay with Terminal Blocks for both Input and Output Interface. Relay with Optocoupler Isolation. Relay supports High-level Trigger or Low-Level Trigger selectable by a jumper. Relay supports Normally Open and Normally Closed.