The Magpul ESK (Enhanced Selector Kit) offers a variety of selector levers for the Magpul SL Grip Module and HK Polymer Trigger Housings. The Magpul ESK results in a modular ambidextrous selector with enhanced ergonomics. It provides a modern rendition of the classic MP5 SSL with updated aesthetics. With easier access to the user-configurable levers the Magpul ESK allows quick firing hand activation and deactivation of the safety and provides for ambidextrous use. Made with high-strength polymer and corrosion-resistant steel. Compatible with three-position S-E-F and Safe-Semi trigger packs. Compatible with HK HK94 G3 93 91 SP5 SP5K and MP5. Made in the USA.