Conversion ring for attaching lens filters of different sizes from camera lens diameters, lens hoods or conversion lenses. Example: If your cameras lens diameter is 67mm and the filter diameter is 62mm, then use a step-up ring of "67 to 62" 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).