[etd]

Looking at mach1 I've found a complete and fairly cheap set to upgrade my upper gearbox with the ics split gearbox system. my main question is whats the difference between:

1) MC-71 Oversize cylinder (Full Capacity)
http://www.mach1airsoft.com/web/cata...om&id=74&cat=4

and

2) MC-58 Oversize cylinder (4 opening)
http://www.mach1airsoft.com/web/cata...om&id=73&cat=4