The Magpul ESK (Enhanced Selector Kit) AR is a modular, ambidextrous selector kit designed for AR pattern firearms that provides user-configurable selectors with modern ergonomics at an accessible price. The selector axle is reversible for 60 or 90-degree throw options and is made of fully-machined, heat-treated chromoly steel with a QPQ finish for extreme resistance to wear and corrosion. The ESK AR includes three heavy-duty polymer levers - Full-Length, Short, and Hybrid - which can be mounted as desired by pressing onto either side of the axle's keyways with zero wobble. The selector pins come in black and red for user preference and act as non-load bearing secondary lever locks as well as selector position indicators. Installing the kit is extremely easy once the grip is removed, and if you ever want to reconfigure your levers all that's required is a small punch or hex key to pop the selector pin back out. The kit also includes a spring and corrosion-resistant detent with low-friction coating for smooth yet positive function. Designed for Mil-Spec AR-pattern lower receivers. Not compatible with select fire receivers. Made in the USA.