The M4E1 Threaded Upper Receiver
features a new angular machined design that helps it stand apart from
standard mil-spec upper receivers. This upper receiver features the same
enhanced body profile as our M4E1 Enhanced Upper Receiver but is
threaded to accept a standard AR15 barrel nut. It is forged from 7075-T6
Aluminum and precision machined to work with all mil-spec AR15 parts.