Skier Hot Mirror IR ND 1.2 Filter 4x4" Use lapping optical glass to provide the best quality of footage. Exclusive unique coating to decrease the reflection and diffusion. Filter thickness of only 2mm, it can be used for matte box and Cokin Z-series filter holder. Exclusive multi-coatings on both side offer crystal clarity. Curve polishing on the edge offer smooth and exquisite quality.