RE-A-2000-4096-BB Routing engine with 2000MHz processor and 4GB memory, Base Bundle CB-T-BB T-Series Control Board for Standalone and Multichassis Systems (this is required for multichassis operations) CB-T-R T-Series Control Board for Stanalone and Multichassis Systems (redundant) RE-A-2000-4096-R Routing engine with 2000MHz processor and 4GB memory, Redundant CB-L-T-BLANK Blank plate for CB on T-series CB-T-S T-Series Control Board for Stanalone and Multichassis Systems (spare) CF-UPG1-1G-S Compact Flash Upgrade Kit for RE-A-2000,RE-A-1000 and RE-S-2000 and CF-UPG3-1G-S Upgrade Kit for 1G compact flash for RE600/1600 MEM-FPC-512-S Optional FPC Memory Upgrade: 512 MB DRAM Module RE-A-2000-4096-S Routing engine with 2000MHz processor and 4GB memory, Base Bundle RE-A-2000-4096-WW-S Routing engine with 2000MHz processor and 4GB memory, Base Bundle