An assembly is disclosed including a first component, a second component, and a spacer component. The first component has a first interface surface. The second component has a second interface surface with a curvature different to the curvature of the first interface surface. The second component is connected to the first component such that the second interface surfaces faces the first interface surface. The spacer component is disposed between the first interface surface and the second interface surface and is configured to be pivotable relative to the first interface surface.