User-configurable levers for ambidextrous use; Easier firing hand access to selector levers; Constructed of high-strength polymer and corrosion-resistant steel components; Drop-in installation; Compatible with Magpul SL Grip Module & HK Polymer Trigger Housings; Compatible with three-position S-E-F and Safe-Semi trigger packs; Exceeds usability and performance of HK pattern SSL/ESSL