SmallRig Mini Matte Box Lite Supports Multiple 4 x 5.65”/4 x 4” Filters -3575 6941590007342 | eBay
Matte box 4x4 - SHAPE
Tilta 4 x 5.65" Carbon Fiber Matte Box MB-T04 B&H Photo Video
4 Reasons Why You Need a Matte Box for Your Next Shoot
Amazon.com : Foto4easy Mini Matte Box,Lightweight Matte Box 15mm Rod Support with Top Flag for DSLR Mirrorless Cameras,Compatible with 67mm/72mm/77mm/82mm Lenses,Supporting 4x4/4x5.65 Filters, Black : Electronics
A Camera Matte Box that works with SCREW-ON FILTERS // SmallRig Mini Mattebox - YouTube