F54 C21 is a two-way 90° corner block for the Global Truss F54 four-point heavy-duty system. It uses 50 mm main tubes (4 mm wall) and 30 mm braces (3 mm wall) in aluminium (Al EN AW-6082 T6). The corner includes 60 mm conical connectors and a 53 cm edge dimension. Overall footprint is 710 × 710 × 520 mm, and the unit weighs 15.5 kg. Finish is aluminium (powder-coated options available).