Great product if you need a mag lock.... - Juggernaut Tactical California Compliant AR-15 Magazine Locking Kit

I (unfortunately) have these on three of my ARs, 2 AR15s and an AR10. Of the maglock convenience products out there, I think the Juggernaut is the best "complete" product and works equally well for either rifle build (i.e. AR10 or AR15). The highlight is the action open button in the back. Although there are other products with a similar look, the Juggernaut is the easiest I've used to remove and/or reinstall. This is necessary whenever you want to clean the barrel, upper or bolt. It simply requires you to unscrew a cap to remove whereas another popular product out there requires one to push the detent back to reinstall (not easy). The maglock itself is okay. It works great for me however t does make loading magazines a bit of a pain. The easiest way is to leave the action open and the second easiest is to pull the bolt back as you're loading the magazine. All in all, a very effective product. Oh, if you do decide to put this on an AR10, be sure to buy the right one as they have different length rear buttons for different makers.