Aero Precision M4E1 Stripped Lower (Kodiak Brown) 
NOTE: This part features a colored anodized finish. These finishes are held to different aesthetic standards than parts finished in black anodizing or Cerakote. By buying this part, you understand that the color of this part may not exactly match what is visually shown on the website, and that the part may also differ in shade when matched with other parts of the same color/finish.

The M4E1 Lower Receiver delivers billet aesthetics in a forged package. This custom-designed enhanced forging is machined from 7075-T6 Aluminum and compatible with all mil-spec AR15 parts. Aside from the visual upgrades, this custom-engineered design provides features that challenge much more expensive billet options and simplify the assembly process for the at-home builder.

M4E1 Lower Receiver Improvements:
Threaded Bolt Catch Roll Pin - Allows for simple installation of the bolt catch and virtually eliminates the chance to damage the finish during installation (pin included). 1/16" Hex Key required for assembly.
Integrated Trigger Guard - Eliminates the possibility of breaking the trigger guard tabs by integrating the trigger guard into the lower, creating a stronger more rigid platform to build upon.
Upper Tension Screw - Allows users to fine tune the fit of the upper and lower receiver using a nylon tipped tensioning set screw inserted in the grip tang of the lower receiver. This provides a tight fit with any standard AR15 upper receiver.
Threaded Takedown Pin Detent Recess - Allows user to easily install the Takedown Pin detent and spring with the use of a 4-40 set screw (no more launching detents across the room).
Increased Magwell Flare - Increased the flare of the magwell to aid in quick and efficient magazine changes.
Marked and milled to accept short-throw safety selectors, but will work with standard selectors as well.
Includes: 
Stripped M4E1 Lower Receiver
Nylon tipped tensioning set screw
Threaded Bolt Catch Pin
Specs: 
Platform: AR15
Material: Machined From 7075-T6 Forged Aluminum
Markings: "Cal Multi", "M4-" Serial Number Designation
Compatibility: Works with Standard AR15 Components and Magazine
Weight: 8.61 oz 
Other: Rear takedown pin detent hole is threaded for a 4-40 set screw. Threaded Bolt Catch Roll Pin (Included).
Finish: Anodized
Color: Kodiak Brown