Compression Tester adapter size ?

[Aok]

I have solve my problem with a old tool I forgot I had, I was looking for a gauge with the rubber base like BILL WILLIAMSON had suggested in a earlier post when I found a old mechanical compression tester I picked up somewhere years ago. The reads were 50, 50, 45,50 which I think is ok.
I 1st used the base to connect to my new tester then used the old mechanical tester readings were about the same