The VLTOR Modular Upper Receiver (MUR) is a rigid MilSpec flat-top upper receiver made to fit all AR15/M16/M4 rifles and carbines. The MUR was developed to give the customer a MilSpec correct upper receiver with a thicker wall, making the MUR upper receiver a stronger platform. This more rigid upper receiver will increase accuracy and reliability, while extending the life of the interfacing components, such as the bolt carrier group and barrel assembly. The MUR is made from a 7075 aircraft-grade aluminum forging. Prior to machining, the forging is fully stress relieved, heat treated, aged twice and undergoes a proprietary cryogenic treatment. The MUR is precision machined and each part finished by hand. There is not a better upper receiver available. The main benefit of the MUR is that it is dimensionally correct. Vltor ensures the reliability and accuracy of our production process by using precision machining equipment, thorough quality control inspections, and a 100% final check of all critical dimensions. When you own a Vltor MUR, you have the highest quality upper receiver available on the market today. Made in the USA. MSRP $199.95.