The Viper Tech MKX2 is a 1:1 replica of the legendary COLT XM177E2, which is the compact version of the Colt M16A1 used during the Vietnam War. It is as it were the father of the modern Colt M4 series. Vipertech has built a very high quality airsoft that is in no way inferior to the original in terms of feel, weight and workmanship. The only downside are the non-existent Colt Markings, which would have made the collector’s view of this ViperTech XM177E2 the perfect collector’s item.