Fotga Dp3000 4"x4" Filter Trays Holder for Fotga Dp3000 Series Matte Box This FOTGA DP3000 4"x4" filter holder was designed for the DP3000 series matte box Such as : M2/ M3 /M4 matte box.Also, you can use it on the other matte box it fit all standard 4x4" filter