Manufacturers AR15 / M16 M16 M16A4 Receiver Extension, 6-Position, New (For Collapsible Buttstock Assembly)
Receiver Extension, 6-Position, New (For Collapsible Buttstock Assembly)

This part is found in the following schematics

Receiver Extension, 6-Position, New (For Collapsible Buttstock Assembly)

Receiver Extension, 6-Position, New (For Collapsible Buttstock Assembly)
Manufacturer: U.S. MILITARY
Model: M16A4, M16
Product #: 293910B

This part is found in the following schematics