Metal parts:
Outer barrel, flash hider and sights.

Description:
The M4A1 Carbine is the most famous and popular of the Marui AEGs. Even so it has some well-known drawbacks that need attention in form of customization to make this AEG perform in level that is required.

Ever since the release in 1998 success of Marui M4A1 AEG has grown stronger with the US Special Forces theme. Regular army units have been adopting the M4 as well and SOCMOD kit for M4 has become more of standard than special for both the real world users and airsofters.

Enough about the real world background, so how about the application? The size of the M4A1 is very compact for most users and there is real difference in using say, M16A2 and M4A1. Long M16A2 is liability in CQB-situations where as M4A1 excels with its easily adaptable stock and shortened barrel. This has been recently demonstrated in real world battlefields like Iraq, where the M16s series have received considerable negative feedback for their lenght in CQB-situations. M4A1 has also the so-called flattop receiver that can take optic mounts and US military is now issuing Aimpoint electric dot sights for many units to be used with M4s.