Originally Posted by Rick Thomson

I don't what the exact size of the arm reamers was, but with the turnbuckle wrench I recommend the Tamiya wrench itself, it's the best fit there is. I know some people using wrenches from other brands, but the all didn't fit as good as the Tamiya one, and as a result the turnbuckles were damaged and the blue went off. Which is something you want to avoid