Those are indeed the Husky "thin rings"
But thin rings do have less low speed sealing and thin rings will always test lower in PSI doing a standard compression test in the same cylinder.
You will need to show me any production saw piston with one thin ring Troll...
The 181 had three types that I ever saw....2 thin ring, two thicker ring and single thick ring.
I can't see a single thin ring piston lasting very long in regular logging use.....particularly around here.
