The bars I have are sprung, so there's a range of adjustment available - I input the details of the vehicle into the checker and Thule says what is needed, so for example the C-Class needs the same setup as a Golf, one small and one medium, whereas the E-Class needs one medium and one large.
I'd try to use the checker on the site of the manufacturer, but saying that I'm not sure that I actually did.
One thing that does make life a lot easier is to either buy everything at once specifying the same key, or find out what lock number your existing stuff has and order from a place that allows you to specify that the new locks are the same key pattern as the existing ones. Having a single key for everything really does make a big difference to convenience.
The bars I have are sprung, so there's a range of adjustment available - I input the details of the vehicle into the checker and Thule says what is needed, so for example the C-Class needs the same setup as a Golf, one small and one medium, whereas the E-Class needs one medium and one large.
I'd try to use the checker on the site of the manufacturer, but saying that I'm not sure that I actually did.
One thing that does make life a lot easier is to either buy everything at once specifying the same key, or find out what lock number your existing stuff has and order from a place that allows you to specify that the new locks are the same key pattern as the existing ones. Having a single key for everything really does make a big difference to convenience.