This is the SparkFun Pi Wedge, a small board that connects to the 40-pin GPIO connector on the Raspberry Pi and breaks the pins out to breadboard-friendly arrangement and spacing, and even adds a couple of decoupling capacitors on the power supply lines. The “Wedge” also makes the initial bring-up process easier - you can plug an FTDI Basic module into the built-in serial port. Each version of this Pi Wedge comes preassembled and can be inserted into the RPi’s GPIO port that allows you to prototype - no soldering required!
The Pi Wedge is compatible with the Raspberry Pi A+, B+, or RPi2 models and it adapts the GPIO header on the RPi to a standard solderless breadboard.
While it will technically with with a mini breadboard, it won’t leave much room for external circuitry. If you love the Raspberry Pi and have been looking to start prototyping with it look no further than the SparkFun Pi Wedge!