Steer clear of the low profile GSO focusers as an easy path, it won't work and they are absolute rubbish.
Even with modifications to better centre the rollers it still sags badly & tightening the locking screw even gently skews the focuser tube in a big way.
As Mr bmitchell once wrote, "two pieces of poly pipe & some gaffer tape would do a better job".
Wish I'd had this advice before buying, would have saved the money & bought a Moonlite.