Our sets of six heavy duty shoulder covers are to be used with our premium canvas saddles,(not the extra large). These shoulder covers are nearly twice the thickness of the ones in the ten packs. Sometimes the chickens shoulders will be missing feathers from feather pecking, or an over zealous rooster may literally be wearing off all the feathers on the chickens shoulders, due to excessive mating. This can lead to open wounds and cannibalism within the flock. At the first sign of excessive wear or to prevent issues, the shoulder covers can easily be installed with any of the Down Under Outdoors premium canvas saddles. The video in the listing shows how to put the saddles on first and then add the shoulder cover. The cover is installed with the largest side towards the chickens head and the shiny side up. It is placed in position prior to closing the flap. Be careful not to have the cover in the way of the snaps closing. If a cover is lost, or eventually becomes unusable, then just use a replacement from these six packs. If the covers get misshapen, which can easily happen if they are not stored flat, or on some birds they seem to easily become a bit rolled, the covers can be removed and ironed with a hot iron. You must use a piece of cloth on top of the PVC. Be careful not to get it too hot and melt the cover. This will restore any bent up and wrinkled shoulder covers back to their original shape.