The device is a DC-DC step-down adjustable voltage converter/stabilizer made with integrated circuit LM2575T. 
Protection against short circuit, overload and overheating. 
Low idle consumption. High output voltage stability. 
The module is used to power devices using up to 1A. 
- Input voltage: 4.5 - 25V DC. 
- Output voltage: 1.23 - 20V DC / 1A. 
- Adjustable output voltage. 
PCB size - 1.85x0.9 inch or 47x23mm. 
When heating the stabilizer, a suitable heatsink must be installed. 

This kit is disassembled, requires assembly and soldering. 
Also available as an assembled module - Product code 1507. 

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)).