Command Arms MCK 3.0 Handgun Conversion Kit for Glock 20/21 Black MCK21GEN3

Compatible with the Glock 20/21. Not compatible with Gen 1 or 2 Glock models due to lack of forward Glock universal accessory rail. Can be used with a huge array of slide mounted optics. No longer is the MCK slide and serration dependent! Utilizing the NEW GEN 3 Charging Handle you can use any aftermarket slides sights or optics inside the MCK.