The Breakthrough Clean Technologies AR15 Lower Block with Pivot Lock is designed for seamless firearm maintenance. By inserting it into the magwell, it provides a snug, secure fit, effortlessly locking in place using the receiver&';s magazine lock. This block can be easily clamped onto any vise, enabling convenient and stable cleaning and maintenance. It features an integrated hammer stop tool, safeguarding the receiver from damage during dry firing. As a bonus, this block comes with a Pivot Lock, ensuring easy access to the barrel and chamber. Elevate your firearm care with Breakthrough Clean Technologies AR15 Lower Block tool, guaranteeing a tight and secure fit for all maintenance needs.