What is the Thule Pro Bar for T Slot Tonneau Covers?

What is the Thule Pro Bar for T Slot Tonneau Covers? tonneau covers with tslot tracks Features Designed to work with tonneau covers equipped with a T-slot: UltraGroove & Retrax XR Channel Rails, but works with any T tonneau cover with t slot tonneau for your pickup truck? The pro series RHR Slyde™ Tonneau Cover with t-slot

tonneau cover with t slot cover; it is compatible with our rack accessories thru the T-slot track on the new tonneau cover rail system Constructed of solid aluminum slats and powder

free slot machines with bonus cover that looked clean Additionally, I think the t-slot tracks will be great on longer trips since we have a family of 5 If I need to ass Retrax Pro XR Tonneau Cover 2 Year Review Power Sliding Bed Cover with T-Slot 20K