Either write, call, or check the website of the manufacturer. You should be able to get another wrench. If you don't this idea, buy a metric wrench from a hardware store and simply grind it down, (much like a "tappet wrench"), so it will fit without any trouble.
I have 3 routers, 2 with the spindle lock and 1 with the 2 wrench system, which is better?? I can't say, I like both.
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