This medium sized perfboard measures 100 x 50mm and features 4 mounting holes in each corner. This perfboard has interconnected rails and rows just like a solderless breadboard, saving quite a bit of wiring over a standard perfboard. There are 6 horizontal power rails; each pair of full length rails is separated by vertical rows of 6 pins. This familiar format makes for an easy transfer of a prototype circuit on a breadboard to a much more permanent shield.