This is a standard '130 size' DC motor. It comes with a wider operating range than most toy motors: from 4.5 to 9VDC, This range makes them perfect for controlling with most of the Arduino Motor Shield, or with an Arduino where you are more likely to have 5 or 9V available than a high current 3V setting.
If you find it hard to fix this motor in your project, you can have a look at the 130 DC Motor Bracket, hope it helps for you.