Sorry no stock at the moment the nvram are not easy for me to buy or very very expensive.
16Kbit plugin NVRAM module with enable switch. The NVRAM modules are ST M48Z12 DIP chips and you can remove and replaced to add more storage space.
The enable card is needed to tell the Neo Geo you have a card inserted.
WIll work with 4 and 6 slot MVS boards. 1-2 weeks delivery