SMTpads is a prototyping circuit board with a grid of pads for 0402, 0603, 0805, 1206, SOT23, and other SMT parts. A grid of 42 mil square pads on 50 mil centers allows SMT components of various sizes and pitches to be mounted. Larger components can span pads. SOIC (50 mil pitch) and DIP (100 mil pitch) integrated circuits can be soldered directly to the pads without adapters. The 2S board has square pads on 2 sides. This allows SMT circuitry to be constructed on both sides. There are unplated holes spaced 4 pads apart for easy connections to the other side. Just insert a wire and solder both sides.