The Thule SmartClamp can be fitted to some Ducato, Jumper and Boxer vans to give you a rail that can be used for various applications, including fitting a Droprack.
You can use a Droprack on a Thule SmartClamp if you have this railing channel system fitted to your van.
You'll need the 751 footpack and 3075 adapter kit to fit a Droprack to the channel on the top face of the SmartClamp system.
