quite a few people didn't like the QR version of this axle. i will say it was kind of guesswork to figure out at first, but very very easy after a couple tries. i've seen complaints from quite a few people, mostly reviews on other sites, but it's not that hard to figure out. very easy actually. never had a problem with it, very simple. some people must not be coordinated...anyway, over time i've thought of getting the gen 2 hexlock axle, but the QR is still really good and will probably keep it. i know its showing not available on the hayes site, but can probably still purchase elsewhere. no tools needed to use, tools needed to instal the gen 2 hexlock.