It's a Hi-Link PM03 3.3V 3W AC-DC Power Converter . This is a PCB mountable module. It has low power consumption, environmental protection, no load loss, high efficiency, high power density.  It has also output overload and short circuit protection. 
Features 
- It is PCB mountable
 
- Low power consumption, environmental protection, no-load loss <0.1W
 
- High efficiency, high power density
 
- Output overload and short circuit protection
 
- Module | Power Supply Module | AC-DC Converter | DIY Projects | Home Automation.
 
SPECIFICATION 
 
| Brand | 
Hi Link  | 
| Model number | 
HLK-PM03 | 
| Input Voltage | 
100V-240V AC | 
| Output | 
3.3V, 900mA | 
| Power  | 
3W | 
| Input Low Voltage Efficiency | 
69% @ 110V AC & Full Load output | 
| Input High Voltage Efficiency | 
70% @ 220V AC & Full Load output
  | 
Maximum input current
  | 
0.2A | 
| Maximum Input Current Surge | 
10A | 
| 
Voltage Regulation | 
±0.2 % | 
| 
Load Regulation | 
±0.5 % | 
| Dimension (LxWxH) | 
34x20x15 (mm) | 
| Pin Distance | 
Please Refer the Image Below  |