What is the difference between Thule's different roof rack systems?

Thule QuickAccess Interface Top T-Track Rubber Strip Replacement thule t slot rack rack installation SwingBlade end cap pivots open to allow full access to the T-slot for easy accessory installs Upper T-track with QuickAccess interface thule slot vervangen It also features a new QuickAccess interface that allows smooth and easy installation and removal of accessories to the t-slot rack with all

thule t slot Rotopax RX mounts 40lbs on-road, 25lbs off-road; T-Slot crossbars only