Golgy A Sunday Gamer takes a good look at the A&K MSK STD Upgrade done by Begadi. This AEG gets fitted with the Begadi CORE EFC System,  Begadi Mamba 30K balanced motor with neodymium magnets, Begadi PRO FLY5 HopUp Bucking with matching tensioner, and Ventilated CNC aluminum piston head with ball bearing.