A smooth zoom or follow focus is necessary when filming and the Fotodiox Elite Focus Handles are perfect for this. The silicone rubber rings are stretchable and have multiple grooves around the outer portion that allow the photographer to adjust the handles to fit just about any diameter lens. The slim design allows for multiple handles to be used on the same lens to give the photographer total control over zoom, focus and even aperture! The handle can be removed and placed into two different positions to get the best grip for the photographer or videographer, so to not get in the way of a shotgun mic or any other accessories placed on the camera.