Heavy Duty In-Frame Box, with Bright Aluminum Finish and Diamond Tread Drop Open Door with T-Handle Locking System. In-Frame Box is designed Heavy Duty for Stepping on or Standing on, making working on the back of your Truck easy. The In-Frame Box is easily mounted to Truck Frame and is mounted behind the Cab. Comes with Installation Instruction and Mounting Kit M3100F.
Installation Instructions: http://www.portoolboxes.com/images/PDF/ISL1010.pdf
Description Sheet: http://www.protoolboxes.com/images/PDF/DST1010.pdf