This is a super-telephoto zoom lens from Olympus (OM SYSTEM). It's the older model, not the current II version. It has been used outdoors, so there are scratches and paint wear on the exterior. I also believe there is some dust inside the lens from normal use. The reason for the issue is that there was a previous error message "Lens not recognized" when turning on the camera. (This symptom is not currently occurring) By the way, once recognized, there were no problems until the power was turned off. OLYMPUS 75-300mm f/4.8-6.7 zoom lens, 58mm filter diameter, Micro Four Thirds mount. - Brand: OLYMPUS - Model Name: 75-300mm - Maximum Aperture: f/4.8-6.7 - Filter Diameter: 58mm - Mount Type: Micro Four Thirds Thank you for looking.