This device is a relay, working as cyclic timer (cyclic time relay). Operating mode is as follow: Work, Pause, Work, Pause etc… 
You can adjust working and pause time between 1 and 120 seconds or minutes. 
When power is on (LED Power is on), the relay closed (LED Relay is on) and keep that position, until end of set ON time (Work), then relay is deactivated (LED Relay is off) for the set OFF time (Pause) . When off time end - cycle repeat from beginning and so on. 
Work time (ON relay) and pause time (OFF relay) are adjusted independently. 
The two times are independent, ie be regulated separately. The time is from 1 to 120 seconds or minutes. Times is adjusted by two trimmer potentiometer.  
Potentiometer “WORK“ adjust devise working time - between 1 and 120 seconds or minutes. To switch between seconds and minutes use jumper. Settings must be done when power is off.  
Potentiometer “PAUSE“ adjust devise pause time - between 1 and 120 seconds or minutes. To switch between seconds and minutes use jumper. Settings must be done when power is off. 
Dimensions for PCB - 68x30mm. 
The output, is relay with: 
- Normally open contact - NO. 
- Common contact - COM. 
- Normally closed contact - NC. 
Relay: 15А/125V DC, 15A/24V DC or AC, 10A/250V AC. 
Power supply - 10 to 14 V DC. 
Current relay is turned off - 8mA, current relay is turned on - 48mA. 

This product is an assembled module. 

The appearance may differ from the one in the photo without changing the parameters of the product (This means that there may be a difference in the elements used (appearance, placement, color, shape or value)).