Olympus Telephoto Zoom Lens Focal Length: 40-150mm Maximum Diameter x Length: 63.5 x 83mm Weight: 190g Compatible Mount: Micro Four Thirds mount system This lens was purchased used. After purchase, I used it about 10 times on an Olympus OM-D. The zoom ring turns smoothly. There may be some minor dust inside, but I have never noticed any impact on the image quality. Please understand that this is a used item before purchasing.