Conversion ring for attaching lens filters of different sizes from camera lens diameters, lens hoods or conversion lenses. Example: If your camera lens diameter is 52mm and the filter diameter is 58mm, then use a 52-58" step-up ring between the camera lens and the filter. Please select the step up ring size that matches the lens filter diameter, lens hood caliber and conversion lens calibers. Installation Method: Screw-In type (*Please note that it is difficult to remove if you tighten too tightly. Ring frame thickness: Approx. 0.2 inches (5 mm).