Our take:  The Golden Eagle Polymer M4/M16 Airsoft Upper Receiver is an upgrade part that quickly attaches to most M4 and M16 airsoft AEG lower receivers.  Additionally, it features an upper optics rail for integration of your favorite airsoft scopes. It comes with all the parts you need, including the metal D-ring, metal top rail, charging handle, ejection port cover door, and forward assist button (push button).

Features:
- Durable polymer construction
- Full metal upper optics rail
- Lightweight realistic design
- Integrated Picatinny rail for weapon accessory attachment
- Functioning ejection port cover
- Quickly attaches to most polymer lower receivers

Specifications:
Construction: Polymer Receiver, Metal RIS
Length:  8" in.
Compatibility:  Most M4/M16 airsoft AEGs

Package includes:  Airsoft M4 upper receiver

Package weight: 1.2 lb