The Quick Cradle heavy duty under mount frame brackets provide a secure connection through trailers for Quick Cradles. These under frame brackets don't require modification to the trailer frame itself, only to the bed. The brackets clamp around the frame, and are secured in place with 5/8 in. bolts. The frame brackets provide a very stable mounting platform for heavy duty Quick Cradles, but suits many other applications for trailer attachments. Installed by drilling through the bed of the trailer to clamp in place - no modification to frame required Provides a highly secure mounting platform for heavy duty Quick Cradles, and many other types of attachments Requires 5/8 in. grade 5 or higher bolts, nuts, and washers for attachment (not included) Designed and manufactured in the USA