"The Magliner Posi-Step retractable underbody truck ramps make loading and unloading safe and easy. A unique Posi-Step surface provides excellent traction while allowing water, small debris, and dirt to fall through and out of the walk path. Its 24"" width is designed to fit a downsized truck chassis. Each ramp is conveniently shipped completely assembled for quick installation. Once installed, simply roll out the ramp and securely store it underneath the truck."