Dimensions: Approx. 9X6.5cm/3.54X2.56"" * Square Port: 12mmX12mm * Weight: Approx. 60g/2.12oz * Easy to install and uninstall. * This small speed crank is made of Aluminum, for rod support rail system use. Sometimes, such a "focus pull" would even be difficult with a follow focus, so the L-shaped metal rod speed crank can be attached in the provided square hole at the center of the wheel. Thus, the hand merely has to spin the rod, which turns the wheel