Robert sent in news this weekend aboout the Viper/Vipertech Colt Model 653 M16A1 Carbine GBB in stock at CWI Airsoft. It is part of the CAR-15 family based on the AR-15 and M16. The Model 653 was part of the M16A1 Carbines with retractable stock and was the most ordered among the other M16A1 carbine models such as the 651, 652 and G54.