NX Filter Frames are required when using the NX Series Holder. The lightweight, aluminum frames are essential to the Holder's slim design and allow maximum ultra-wide-angle lens compatibility. The frame also protects the edges of the filter and allows you to handle filters without touching the glass.The 100mm x 143.5mm frame will hold most square filters, including other manufacturers, that measure 100mm x 143.5mm x 2mm thick.Compatible Cokin filters:Nuances Extreme ND8, ND64, ND1024Nuances ClearskyNuances Infrared 720Filters and frames are sold separately to accommodate different Cokin holder systems. | Cokin | | NX Series 100x143.5mm Filter Frame | Best Buy