Specna Arms CORE Series M4 AEG (Model: M4 PDW / Black)

Features Ultra lightweight fiberglass reinforced polymer receiver Licensed Rock River Arms logos Nylon fiber furniture Metal barrel assembly, flash hider, charging handle, and sling swivels ESA quick spring change system allows the spring to be changed without the need to disassemble your gun Rotary type hopup with 6.03mm tight bore barrel 380 fps spring pre-installed from factory, optional 310 fps (M90) spring included to reduce muzzle velocity Freefloat quad rail handguard