MEM-C4K-FLD64M Catalyst 4900M Compact Flash, 64MB Option MEM-C4K-FLD64M= Cat 4500 IOS-based Supervisor, Compact Flash, 64MB Spare MEM-C4K-FLD128M Catalyst 4900M Compact Flash, 128MB Option MEM-C4K-FLD128M= Cat 4500 IOS-based Supervisor, Compact Flash, 128MB Spare MEM-C4K-256-SDRAM= 256 DIMM DRAM for Supervisor II-Plus-10GE MEM-C4K-FLD64M-RF C4000 Sup IIIIV Compact Flash Disk 64MB REMANUFACTURED MEM-C4K-FLD128M-RF C4000 Sup IIIIV Compact Flash Disk 128MB REMANUFACTURED