I ordered two of these, one for my Ruger AR556 with a M-Lok free float rail and one for my PSA AR 15 with MOE hand guard. These are sturdy and light weight and install very easily on the M-Lok free float rail or Magpul M-lok SL hand guard.. I recommend Loctite on the screws as these don’t come with thread locker like the Magpul brand.
https://www.amazon.com/UTG-PRO-Standard-Swivel-Adaptor/dp/B018ZS5A0S

