The module is made of an electromagnetic relay operating on 12V, controlled by an optocoupler and a transistor mounted on the printed circuit board. 
Galvanically separated input (optocoupler). 
It is used in the control of powerful consumers (fans, motors, lamps, powerful LEDs, etc.) as an electronic switch or circuit breaker controlled by a microcontroller, etc. 

Parameters: 
- Supply voltage: DC 12V (observe polarity). 
- Input signal for relay operation: DC from 5 to 12V (observe polarity). 
- LED indicating the presence of supply voltage: D3. 
- LED indicating the presence of an input signal: D2. 
- Relay: 15A/125V AC, 15A/24V DC, 10A/240V AC. 
Contact Current - AC (under high pressure) - 15A/120V AC. 
Contact Current - DC (under high pressure) - 15A/24V DC. 
Contact Current Rating 15A. 
Contact Voltage - max 240V AC, max 100V DC. 
Relay output: 
- Normally open contact - NO. 
- General contact - COM. 
- Normally closed contact - NC. 
Size of PCB: 53x29mm or 2.09x1.14 inch. 

Attention !!! 
When working with voltage above 24V, all rules for safe operation with high voltage must be observed. 

This product is a fully assembled module.
It is also available as a DIY assembly kit - Product code 1285 (separate product).