This kit is all you need to install the square tube V-Bend aluminum cross-member to your aluminum I Beam boat trailers. The tube measures 3 inches tall x 3 inches wide x 80" inches long. While this is considered an industry standard 80-inch cross member, The tubing has a 1/4-inch wall thickness. Boat trailer cross members are normally attached using U-bolts and bolts. If you have an aluminum framed boat trailer that has galvanized cross-members, this is a great upgrade to switch the whole trailer to aluminum. The Stainless-Steel U-Bolt 1/2" x 3 1/8" x 4 5/16" is typically the recommended U-Bolt for mounting this product to your I-Beam frame. This component has a 3" drop that is specifically intended to prevent impact from the V-Hull on your boat when loading and unloading at the ramp. This component is extremely important on your boat trailer as it is responsible for supporting the weight of your boat and keeping the frame square. Kit contains: 1ea 80-inch V-bend aluminum crossmember 2ea 1/2" x 3 1/8" x 4 5/16" Stainless Steel U bolts 2ea 1/2"-13 x 1 1/2" Stainless Steel hex head bolts 8ea Stainless Steel flat washers 4ea Stainless Steel nuts 4ea Stainless Steel lock washers 2ea Stainless Steel nylocks