ARRI Tech Tip: Lightweight Matte Boxes - How to use 138mm diopters in a clip-on matte box? - YouTube
ARRI Lightweight Matte Box LMB-4x5 - YouTube
ARRI LMB-25 Clip on mattebox 4”x5.65” 3 stages – Rental | We are Filmmakers
Arri LMB-25 3-Stage Clip On Matte Box – Camera Ambassador Rentals
Amazon.com : Fotga Mini Lightweight 4x4 4x5.65 Clip-on Lens Matte Box for DSLR Mirrorless Camera A7 A7R A7S II III IV Z6 Z7 II RP R3 R5C GH5 GH6 BMPCC 4K 6K,Compatible