"CONSIST OF 1 DISC AND 1 HUB,DISC MATERIAL IS 0.007 IN. THK BY 1.100 IN. DIA CLEAR PLASTIC ACETATE PER L-P-504 TYPE 2,0.180 IN. DIA THRU HOLE CENTER OF DISC,HUB MATERIAL 0.375 IN. DIA BY 0.125 IN. THK ALUMINUM ALLOY RND 2024-T4 PER QQ-A-225/6,FINISH MIL-C-5541 CLASS 1A,0.1248 IN. DIA THRU HOLE CENTER OF HUB DIA,2-56 UNC-2B THREADED THRU HOLE IN SIDE OF HUB TO ACCOMIDATE SET SCREW"