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

T-Slot Bar 140 t slot bars T-Slot Nuts with threads and Groove Profiles that can be machined as required are installed in a groove to provide a counterpart for screws type of slot Rectangular T Slot Bar Straight Connector for T Slot Aluminium Profile, For Industrial, Thickness: 5mm

t slot brackets T-Slot Nuts with threads and Groove Profiles that can be machined as required are installed in a groove to provide a counterpart for screws