9 Volt Battery Clip Connector Buckle

This is a 9v battery cable. It is commonly used with the OOPic Module. This has a polarized connector and can also be used for other 9v battery applications. 
Use a 9V battery clip to easily connect your 9V battery to your Arduino. Use one with leads to connect your battery directly to a breadboard or the Vin pin on the Arduino. You can also buy a clip with a barrel jack for plugging directly into the Arduino.