SP2-50x50-2S (Two Pack) SMTpads, Size 2, 50x50mil Pads on 2 Sides, 2 Sided PCB, Size 2 = 100 x 80mm (3.94 x 3.15in) Package of two SP2-50x50-2S prototyping boards. Square SMT pads on 0.050 centers for surface mount components. Pads on both sides. Double-sided high-quality FR4 glass-epoxy circuit board with unplated holes. 1oz/ft2 copper with an anti-tarnish coating for easy soldering. Lead free and RoHS compatible. 0.031" (0.79mm) holes (unplated) for connections to the other side. Just insert a wire and solder. Size 2 = 100 x 80mm (3.94 x 3.15in), 1/16" thick (1.6mm). Four 0.125 mounting holes.