This is a general purpose SMD prototyping board.
Small, cheap to manufature.
It fits most common hand solderable SMD packages :
- 1.27mm SOIC
- SOT-23-x
- SOT-89
- All resistor / capacitors / 2-pin components up to 0402 size (Why would you prototype with 0402 is an other question)
A ground plane covers the whole back of the board