MCX VIRTUS UPPER ASSEMBLY - 16" 5.56 NATO is rated 5.0 out of 5 by 2 .

Rated 5 out of 5 by Steve B from Excellent, except not the color I was expecting I already owned an 11.5 MCX Virtus, and liked it so much I thought I would add a 16" model to my stable. I ordered an upper from Sig, and utilized the included trigger and stock adapter to mount the upper to a Centurion Arms M4 lower. Everything fits and works perfectly. My only complaint is that the upper was black rather than Sig grey. I solved the problem by replacing the original handguard with a 12" grey one. Perfect!! The MCX Virtus is a great system and I am very satisfied. Highly recommended.