2 questions about hexes

A few days ago I started a topic because I stripped my LST hexes and wanted to know how to fix it, but it went wrong Anyway, does somebody have good experience with LST1 hexes? Or should I upgrade my LST1 with a LST2 performance kit with aluminium hexes? (That would suck because I've still got 3 good tyres + rims)
And question number 2; how should I measure hexes? Losi says that the LST1 got 17mm hexes, but how the f*ck do they measure that? I measured this:



None of them is 17mm, so how do they measure 17mm? Or am I just stupid???