The set of 5 prototype boards contains these standard sizes • 40mm x 60mm • 20mm x 80mm x2 • 30mm x 70mm • 50mm x 70mm all the boards are green. the rings are of premium quality with 2mm diameter mounting holes. re-soldering through hole parts is a non issue compared to other PCB copper clad prototype boards. very forgiving in other words. all the holes are numbered on the sides in white numbers and letters for easy transfer of the schematic to your project prototype. On both sides of the boards are connector pads, a small solder bridge eases the use of buses in your work.