Mil-spec with MIL-8625 Type 3 Class 2. These lowers are made using the most advanced aerospace manufacturing technology to produce the industries finest, forged Mil-Spec lowers. Machined on a multimillion dollar, automated, manufacturing system which enables the production of an unequaled quality and value-driven lower receiver. These forged lowers are quality made using material is 7076-T and are marked CAL MULTI to accommodate most builds. Finish is Black Hardcoat Anodize per MIL-8625 Type 3 class 2. Serial number prefix is NGP. Fire selector markings are SAFE and FIRE. Made in the USA by Seiler Instrument & Manufacturing Company. These lowers can only be shipped to FFL holders at the address as it appears on the FFL. The FFL must be on file with our company before we can process and ship your order.