The ProtoShield makes it easy for you to design custom circuits. You can easily solder TH or SMD ICs on the prototyping area to test them with your Arduino board. The SMD area is designed for a maximum of 24 pins SOIC integrated circuit and the TH area contains a lot of space for the needed components around your project. You can even stick a mini breadboard (not included) on the protoarea for solderless operation. The proto area includes also two power lines (IOREF and GND), two LEDs pads and SPI signals breakout pads for boards with SPI only on the ICSP header like Zero.