【Square ND Filter for Matte Box】Compatible with Tilta SmallRig Matte Box, Mini Matte Box, Filter Frame. The NEEWER square ND1.8(6 Stops) 4" x 5.65" / 10.16 x 14.35cm filter enables more control over shutter speed and aperture, avoiding overexposure and helping to balance image exposure, perfect for shooting in bright sunlight, creating motion blur. Ideal for professional photography and videography | 【Professional Build with HD Optical Glass】Made of HD optical glass, this filter delivers high clarity pictures without compromising image quality or adding color cast. Not being directly screwed onto lens, the square ND filter can be used for lenses of various focal lengths when mounted on a matte box | 【ND1.8 Filter with 1.56% light transmittance】The ND1.8 neutral density filter blocks 6 stops of light from entering into camera lens and features 1.56% light transmittance. The number 1.8 stands for the filter’s optical density. Optical density grows and light transmittance lowers as the number goes up | 【Double Sided Multi Layers of Nano Coatings】 The multiple layers of Nano coatings on both sides make the filter scratch resistant, water repellent, oil proof and fingerprint resistant. Use the included cleaning cloth to clean the filter | 【Super Slim & Lightweight】 0.16"/4mm thick and weighs only 5.12 oz/147g. This ultra slim and lightweight filter, barely noticeable weight to your filming setup when mounted on. Store it in the carrying case for storage or for when in use on the go