Excellent arm brace! - KAK Shockwave 2M Blade

Several years ago I built from scratch a 9mm AR style Pistol using a Shockwave Blade 1.0 Pistol Arm Brace and it has worked flawlessly! However, since the Lower Receiver is dedicated to the Colt SMG style of Magazines, I got a new Lower to handle Mil-Spec 5.56mm Magazines for the AR-15/M16 Firearms. After building my AR-15 Rifle with an M4 style Stock, I purchased Palmetto State Armory's 10.5" Classic Pistol Upper, fully assembled. I then got the KAK Shockwave Blade 2M Pistol Arm Brace. Removing the M4 Stock and AR-15 Rifle Upper, then installing the KAK Shockwave Blade 2M and Palmetto State Armory 10.5" Classic Pistol Upper, takes only about a minute!