This complete lower-parts kit includes the L2S 2 Stage Liberty trigger to help you finish your high-quality build. Every component in this kit is made to exceed Mil-Spec to ensure ultimate reliability in your AR. The SOLGW bolt catch and spring are cast from AISI 8620 per USGI TDP while the KNS Precision Machine safety and takedown pivot detents are made from hardened stainless steel.