The TopStop cover is a must-have accessory for anyone using AR-15 or M4-type rifles. Designed to securely snap onto the upper receiver when detached from the lower receiver, it provides exceptional protection during storage or transport. The TopStop creates a complete seal, preventing debris, dirt, and fouling from contaminating the internal components. It also ensures that the bolt carrier group and charging handle stay firmly in place, even when the upper receiver is moved or handled. This practical and reliable cover helps keep your rifle in top condition, ready for action whenever you need it. Designed to snap-on most AR-15 or M4-type upper receivers, offering easy and secure installation for a wide range of AR-based platforms This will only fit uppers that are detached from the lower, ensuring compatibility with specific firearm configurations It features tough polymer construction