Designed to be the perfect mate for your tonneau cover, these TonneauMate toolboxes work on most full size trucks with or without a cover. They feature durable construction with an aluminum frame and a composite design. They will support heavy loads of up to 200 lbs. and are built to last. These TonneauMates mount to your bed side to allow for the use of the entire truck bed floor and easy access to the bottom of the toolboxes. This lockable 55in.L x 22in.W x 15in.H box features a universal design that will fit most full-size trucks, even under a tonneau cover.