Amazingly complete development board. Large rugged standard FR4 material with 2oz copper each side allowing multiple soldering attempts and moderate power handling. 3000 plus pads and 4, .125″ mounting holes. Top pads are round, bottom pads are square allowing use of discrete SMD components. Power and ground rails on 2 sides plus a ground shield in the center circling the perimeter. Pads connected in sets of 5 for speedy assembly.