Patent attributes
A component which is configured to be joined to a further component in a preselected relative orientation is disclosed. The further component has an interface surface and the component is configured to contact the interface surface when joined to the further component. The component includes a surface disposed on a side of the component intended to face the interface surface when the components are joined, a plurality of recesses formed in the surface, and a plurality of spacer elements. Each recess has a preselected orientation relative to the component, the preselected orientation being selected in dependence on the preselected relative orientation. Each spacer element comprises a contact surface configured to contact the interface surface when the components are joined. Each spacer element is disposed in one of the recesses such that the orientation of a given contact surface is defined by the orientation of the corresponding recess.