This is a four wire cable assembly to one end with a 4 pin JST SH connection.
10-pin socket with 2mm pitch that mates with the popular XBee radio from Digi.
This USB breadboard power supply kit provides power source from any USB port and outputs a fuse protected and regulated 3.3V. The .1" headers are mounted on the bottom of the PCB for simple insertion into a breadboard. Pins labeled 5V/GND 3.3V/GND plug directly into the power lines.
This can equip your Arduino with mass-storage capability, so you can use it for data-logging or other related projects. All new microSD shields have a voltage converter chip on-board that converts the Arduino 5V signals to 3.3V signals in accordance with SD specifications.