Installation Help-Multi-Controller Button EOS 1 D MKIII 1DS MKII 5D MKIII At the request of our customers, we supply both styles of Multi-Controller button and button covers separately. If the Multi-Controller Button switch is broken off, read no further. You will need to replace the back cover assembly. The switch is not available separately from the back cover PCB and the back cover PCB is not sold separately from the back cover assembly. Multi-Controller Button for CANON EOS 1 D MKIII 1DS Read More...