The KM4 Series complete upper receiver has the forward assist button and ejector port door preassembled, and also comes with the charging handle and mock bolt plate. This piece fits all KM4 Series except for the new KM4 KR series, which means it is compatible with all SR, CQR, and Battle Rifle AEGs, as well as the KM4A1 and the Commando.
The RM4 and VM4 one-piece upper receiver fits all KWA RM4, VM4, and Ronin Tactical Series rifles, including the original Magpul PTS ERGs. (Not compatible...
The KWA metal receiver carry handle is made to fit almost any railed AR-15 or M16 style receiver and is made of durable metal alloy. This assembly comes complete with toolless knobs to easily attach and detach the handle, and is strong enough to carry the weight of any full metal AR-platform rifle. Use this to customize your KM4, RM4, or LM4 to the look you want. Features a level channel for installation of aftermarket receiver carry handle rail attachments, as well as a sight that has adjustment knobs for windage & elevation.
The CQR polymer lower receiver, with either Mod 1 or Mod 2 trademarks, are standard replacement receivers for all CQR AEGs, but will fit all KM4 rifles.
You can specify whether you would like the Mod 1 or Mod 2 trademarks on the side of the receiver by entering a note at checkout. If no note is present, you will receive either receiver, but please note that the receivers are otherwise identical.