I'm very happy with my USA Ohmmeter as well. Would recommend it. When I first got one, I built a number of coils that I "set up" on Steam Engine, built as close to spec as possible (ID, leg length, etc), and it was off (every time) by their stated margin of error (.018Ω). But it was always + .018, so I knew how to make sense of that reliably. I sent that one to a friend, overseas, and had to buy another. The second one seems to be dead-nuts on . . . every time. I still build setups (coil configurations) that I "sketch up" in Steam Engine, based on what I want from a particular build; and the USA Ohmmeter is right there, reading the same numbers that the math says it should be.