Includes 3 boards and serves as a project shield for use with Arduino Uno. Hole patterns match exactly the I/O pads on two edges of the Arduino Uno and it will stack above the Uno using included header pins. Hundreds of different Arduino projects can individually fit nicely on this board. Also can be used as a solo Protoboard - will accommodate standard electronic components having wire leads; over 230 plated thru holes as well as an SOIC flatpack pattern (up to 14-pin), LED pattern and pushbutton pattern. Fiberglass substrate for long life for use with any frequency. Two ounce copper pads with a quality solder plating and solder masked for easy soldering without bridging. Plated through donut pads, solder-tinned and solder mask on both sides of board. Board size: 1/8" thick, 2.126" width x 2.10" length. Holes accommodate standard component leads and are plated through. Header strips are 16 contacts long and are included.