Used this and 2 Park TL5s to mount my Schwalbe Marathon Plus'. 28mm onto Alex R500s. Really tough. Had to use liquid soap, too. The height of a given rim is also important. 25mm SMPs onto Sun CR-18s was relatively easy. But, on my high flange fg wheelset they were a *****.

That being said when I have had the rare flat or slow leak they do come off and go back on much easier than they mount. All of my bikes are equipped w/3 Pyramid 'flat spoon' tire levers w/t edges and burrs filed off. The only place online I know of to get them is http://www.bikepartsusa.com One's lbs probably has them as well. They're only around 4-5.00USD per set.