It's a laminated disc pack, used in a Thomas DBZ-263 coupling. The third link is for the Thomas coupling, with drawings of the coupling assembly and the sizing chart that shows the 263 coupling has an outside diameter of 7" and the drawing shows the disc being a little smaller in diameter.

It's a laminated disc pack, used in a Thomas DBZ-263 coupling. The third link is for the Thomas coupling, with drawings of the coupling assembly and the sizing chart that shows the 263 coupling has an outside diameter of 7" and the drawing shows the disc being a little smaller in diameter.

References:

https://gsexp.com/products/air-conditioning-units/mechanic/shim-kit.html

https://www.cmpcorp.com/product/rng-0620/

https://www.rexnord.com/cmspages/getfile.aspx?guid=361113bd-0841-41e2-99f5-9a...