The WonderPana Free Arc Step-Up Ring provides the freedom to use, share and rotate 66 and 145 filters on all of your regular lenses. Fotodiox step-up rings are made with precision out of premium grade aluminum. Every ring is inspected to ensure smooth mounting and is polished and finished with anodized matte surface for professional appearance. Step up rings allow larger sized filters to fit on lenses with smaller sized filter threads. This step ring will allow the WonderPana145 filters (with a 145mm thread) and the WonderPana66 filters (6.6x8.5" rectangle size) to fit on lenses with a 95mm threaded front. Smaller step up rings can be used to adapt to smaller sized lenses (ie; if your lens has a 86mm filter thread, the 86-95mm and 95-145mm step up rings would be used together) and can be purchased separately. Fotodiox Pro ND Filters are true neutral density filters designed to darken the image. They features an even, neutral gray color for creative photography applications. The ND16 filter offers a +4 stop EV value which allows you to slow down the shutter speed or use a larger aperture in bright light conditions. The Graduated Neutral Density darkens the sky while leaving the foreground unaffected, perfect for shooting sunset or sunrises where the sky is blown out and the ground is dark, allowing you to capture an image closer to what the human eye naturally sees. These two filters combined are a perfect combination for times when you want to darken the overall scene and darken the sky even more so, such as beach or snow sunsets & sunrises for example. Fotodiox ND & Grad ND filters are a true neutral grey and do not color cast the images.