These adapters are great to attach the suction cups when mounting inside the vehicle on a glass roof. They are simple, rugged and don't add much weight. Like all Striker gear they have no sharp edges, align perfectly with the perimeter holes and can be mounted on the sides or front and rear. This might be important when trying to match the spacing of a rail. There is a low-profile version as well so think through what you intend to do or do what I did and talk with Bryan to better fit your application.
