The slot on the arm where the shock mounts is about 2 mm smaller (narrower) on the Moog arm when compared to the Eurospare. They're aluminum but I never torqued them beyond spec so I'm not sure if they are built that way or tightening them closed the gap a bit. I tossed the Mevoteck arms but I did compare them to the Moog when I switched them out and they measured the same. That's my best guess anyway.