Camera Accessories
9.solutions Box Corner Coupler
9.solutions Box Corner Coupler, Adapter for Connecting 50 mm Tubes, For softbox frames, Can be easily integrated into existing truss systems, 3 x 50 mm mounts, Weight: 880 g, Max. load capacity: 100 kg, Includes a set of screws
https://www.bizrate.co.uk/cameraaccessories/9-solutions-box-corner-coupler-oid35781767788.html