Add to Cart Compare Quick view 21" (Height) x 22" (Depth) Mounting Brackets for Trailer Tool Box $83.99 Brackets for Installing Aluminum Tool Box. Suitable for 18" (Height) x 18" (Depth) Toolboxes or Step Boxes.Size: 21" (Height) x 22" (Depth)Heavy duty 3" Steel C-Channel with universal hole pattern for easy mounting.Black powder coated finish for... $83.99 Add to Cart Compare Quick view