Square Fittings End Connectors are made of durable galvanized steel. These Square End Connectors are heavy-duty framing brackets for either metal or wood structural beams. Available in multiple sizes, the steel Square End Connectors fit 2x2 metal beams, 2x4 nominal wood beams, and1.5" Sq. wood beams. Easy to install to create a sturdy frame, uses carriage bolts for installation, not included.