Yea - Stainless. What I liked about them is they gave 2 data points. Max and Min; while the Avery gauges gave one data point - (optimal, I presume (never used the Avery gauges)). So for example, if I wanted to be on the low end (fiberglass) I could tell, but still be within spec.
No idea what I paid for them. Bought them 20+ years ago.
Dave