For building connections or stays of optional length and angle.,Will connect to all XC beam sides, or 44 mm square beam ends which accept M8 threads.,Each bracket requires two M8 x 12 screws see stock no. 527-482, and two M8T-slot nuts see stock no. 331-4289 for fixing beam sides, or 2 off M8 x 25 screws see stock no. 527-511 for fixing beams to ends.