typically anywhere from 18 inches to several feet in height over the bed the first height may be different for each wall the first wall 207 and the second wall 208 thus rise vertically from the bed to a distal end 130 when the plurality of telescoping extension poles 145 in each said wall is fully retracted the trailer 105 includes a first cap rail 140 atop the first wall 207 and a second cap rail 141 atop the second wall 208 these cap rails are sometimes referred to as side rails and each forms a top cap or cover on the wall usually only the side walls have side rails or cap rails the system 100 includes a plurality of telescoping extension poles 145 vertically positioned within each of the first wall 207 and the second wall 208 each telescoping extension pole in the plurality of telescoping extension poles 145 includes a plurality of pole sections that is two or more pole sections thus there is always a pole top section 305 and a pole bottom section 315 with any number of additional pole sections in between preferably the plurality of pole sections includes a pole top section 305 a pole middle section 310 and a pole bottom section 315 the pole bottom section 315 is typically fixed in position and the remaining pole sections are extensibly nested together within the pole bottom section 315 the pole top section 305 is also typically connected to the cap rail so that when the pole sections are extended the cap rail linking.