We have 3 types of Roof Box fittings to attach to roof bars which are shown below;

Clamp (top 3), U Bolt (Bottom left) & Thule Easy Snap U Bolt system.

The Top clamp is used on our Hapro Traxer boxes which can fit bars up to 95mm wide

The Middle clamps are used on the majority of our Thule, Exodus & Halfords Advanced boxes which can fit bars up to 80mm wide

All 3 types of clamp are very simple to attach / detach to roof bars.

For the 2 Exodus roof boxes which use U bolts, by default we use the Thule Easy Snap U Bolt system (bottom right) but alternatively the Traditional U Bolt fittings (bottom left) can be used instead if you prefer. These fit bars up to 80mm wide. These 2 roof boxes can also have the T bar fitting installed if required.