Product DescriptionThe Luth-AR Builder Lower Parts Kit is designed to help complete an AR-15 "mil-spec" lower receiver build while leaving key performance and preference items up to you. This kit provides the essential small parts needed for assembly, but intentionally excludes the fire control group (trigger components) and pistol grip so you can choose your own. Luth-AR uses American-made components produced to mil-spec drawings with quality materials and heat treat processes, and the springs are made from a combination of 17-4 stainless steel and certified mil-spec steel wire.Product Highlights AR-15 builder lower parts kit for completing a stripped lower while customizing trigger and grip choices No metal injection molded (MIM) parts-components are investment cast and/or machined to mil-spec drawings Includes core lower-receiver small parts such as bolt catch parts, selector parts, takedown/pivot pins, detents, and springs Springs manufactured from 17-4 stainless steel and certified mil-spec steel wire for reliable function Made in the USA by Luth-AR for AR-platform builds and repairsSpecs Brand Name: Luth-AR Manufacturer Part Number: LRPK-BLDR UPC: 859992007654 Platform Fit: AR-15 (mil-spec lower receiver) Kit Type: Builder lower receiver parts kit Included / Not Included: No fire control group (trigger components); no pistol grip Construction Notes: Investment cast and/or machined parts to mil-spec drawings; heat treated per spec; no MIM Spring Materials: Combination of 17-4 stainless steel and mil-spec steel wire (certified) Approx. Package Dimensions: 6.0 in (L) x 2.0 in (W) x 1.0 in (H) Approx. Weight: 0.50 lb Country of Manufacture: USADisclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product's manufacturer.