A mountainous or valley-shaped curved part 13 is provided in a part of a footstep guide rail 3 for guiding a movement of footstep rollers 5 linked by a footstep chain 7, the part being positioned in the vicinity of a drive sprocket 9. Using the target metallic solutions results in damage free use to surrounding optical components since no debris are formed. The elongate member has a pre-formed curved orientation that at least substantially matches an inside surface of a cochlea, an implantable orientation different to said pre-formed orientation that allows said member to be inserted into an implantee’s cochlea, and an at least one intermediate orientation between said implantable orientation and said pre-formed orientation. The row and column contacts may be redundant to improve the yield and life time of the display. Further, the source device may receive data from the sink device via the wireless peer-to-peer connection.