What is the segmented flat spacer that came in the bag with the 3 blades? Thickness of a washer. I sent a photo to Dewalt and they can't tell me what it is or what it's used for??

The only items officially included are: the tool, battery, charger, depth guide, sanding pad, universal accessory adapter, 3 blades, and sandpaper sheets. There is not a flat segmented washer/spacer that comes as a standard part with the kit.