These little clip things hold a special self locking threaded nut have to be fitted the entire length of the plane a few inches apart on these aluminium strip things, of which there are several of them the length of the plane, each clip thing has two rivets holding it in place and they have to be countersunk into the aluminium , the stainless steel screw that will go through these is what holds the aluminium panels to the fuselage. There are a LOT of them