Command Arms MCK21TA: The MCK (Micro Conversion Kit) is the next generation of conversion kits from CAA USA. It is a lightweight and sturdy platform for various handguns and has a barrel shroud made of aluminum with a polymer body. The stabilizer enables one-handed firing for better shooting performance. It also comes with a Velcro strap fastener which provides a custom fit to any user. The MCK improves accuracy dramatically up to 200 yards, utilizes ergonomic finger groove grip, a top and side Picatinny rails, right-folding arm brace and a built in charging handle. It is the most cost effect, fastest assembly / disassembly conversion kit on the market. The Advanced kit features a thumb rest, flip-up sights, sling and swivel, and a flashlight. This model is compatible with Glock 20/21 Gen 3 and has a flat dark earth finish.