Sure Grip II Hybrid Reactive.
1500 grit polished.
Hardness of 75-78 D-Scale.

Orbiter II Core in 14-16#.
Modified Orbiter II Core in 10-13#.

16# RG 2.60 Diff 0.020
15# RG 2.61 Diff 0.018
14# RG 2.63 Diff 0.017
13# RG 2.67 Diff 0.017
12# RG 2.67 Diff 0.017
11# RG 2.73 Diff 0.012
10# RG 2.77 Diff 0.015