Read this before buying. - Phase 5 Weapon Systems Inc 90 Degree Ambi Safety Selector AR15/AR10

Easy install, and the fit was fine, but it the long arm on the switch had a burr right where your thumb would sit. That could be fixed by some light sanding, but the bigger issue is that the short arm hits your trigger finger when you put the weapon on fire... essentially NOT putting it on fire (the switch stays in no man's land). If you're doing drills the short switch also rubs on your trigger finger.