Let James from WE do the talking....
Contents:
New System M4 with PTW-like split gearbox
Raptor Rail System(modeled on Remington Military R-4 Gas Piston Carbine's design)
Dual Mag for their GBB M4(gas reservoir on one side and BB's feeds from the others)
XDM IPSC Custom
http://youtu.be/78PLM7iq-BM