Upgrade your aluminum I-beam boat trailer with this heavy-duty square tube aluminum cross-member. Measuring 3 inches x 3 inches x 59 inches , with a 1/4-inch (0.635 cm) wall thickness, this cross-member is designed to withstand the rigors of towing your boat. While the length may vary 1/2", this 59 inch cross-member is an industry standard size, making it a versatile choice for most aluminum I-beam trailers. With its sturdy construction and corrosion-resistant materials, this cross-member is an essential upgrade for any boat owner seeking a reliable and durable towing solution.