1. Designed to built to strengthen the existing basic truck rack style.Each two of the Bracket Bar are jointed with 6 / 4 Grade 8 Carriage Bolts; adding a total of TEN Carriage Bolts built on each upright poles.
2. Comes with two of the One-piece handrail, Which provides the ''Grab and Hop'' convenience of getting on the truck bed.
3. It features the extendable top cross-bar which can be adjusted for different sizes bed width. The adjustable range covers inner bed width from Min. 51'' Max. 71''. The height is 30.5'' to the clearance and 28'' to the cross bar.Fits 5.0'~8.0' bed.
4. The special design of the support bars allows it to be fitted with most types of toolboxes.

The upright plate is a flat L-shape base which has FIVE drilling holes for flexible installation and you only pick two that fits your truck; and yes, we provide all bolts and nuts in the hardware package for installation.
As of now, some compatibilities cases we have heard are:
> Camper shells & Tonneau covers will affect the installation of this unit; 
> Bed rail top made of fiberglass instead of metal for some rare truck models like F-150 super-cab, customers complaint it not sturdy for heavy-duty purpose after making holes; 
> There are track system installed on the inner bed-wall like the New Toyota Models which blocked our mounting plates;
> Bed width is too small for the minimum extension of 51".

P39-MC/RC Upgrade Single Middle Cross Bar and Rear Bar