1,2,4, or 6 Slot
The number of games allowed on a Neo Geo MVS arcade unit. Since the games game in separate cartridges to lower costs (and promote the home system), MVS boards were designed with slots for the cartridges. More 4-slot cabinets were produced than any other. 6-slots are very large boards, and sometimes cannot fit in all cabinets. 6-slots have been known to have reliability issues, but this can be averted through proper care.