Anyone know what I am referring to? They are 2.5" wide, about 6" long, and about 1/16" thick, with a hole in the center for the centering pin. They are placed in between the leafs. Are these necessary to put in my leaf pack that I am building with my existing XJ leafs, and if so where do I put them in the packs? I figure they are to help separate the leafs a bit and make it easier for them to slide back and forth when flexing.