The Thule SquareBar 4-Pack Adapter is an around-the-bar adapter for fitting winter and water sport carriers on square bars. It is compatible with the Thule SnowPack, Thule SnowPack Extender, Thule DockGlide, Thule DockGrip, Thule Hull-a-Port Aero. Secure your gear with ease thanks to the Thule SquareBar 4-Pack Adapter!