Outwell says about the Dual Beading Connect Set 7-7+5 mm
The 5mm is suitable for rails fitted to wind-out canopies such as those found on some models by Thule and Fiamma while the 7mm i perfect for aftermarket rails like Reimo, Mercedes Benz factory rails and also some wind-out canopies. Use together to attach an awning to a VW California rail.