Check the listing for details. MEM3631-128D= 128MB Memory Cisco 3631 Router DRAM. Condition: New. Listed at 9.00 USD. MEM3631-128D= 128MB Cisco Router DRAM Buy two to make MEM3631-64DU256D 256MB Kit Compatible with Cisco Router 3631. 3rd Party. Guaranteed. Normal 0 false false false EN-US X-NONE X-NONE Warranty: Lifetime Replacement Warranty. Support: Email us through eBay Premium Quality: Brand name parts only-no unknown and overclocked parts. All memory modules made from major brand memory chips such as Micron, Samsung, Elpida, Hynix, Promos, Infineon/Qimonda. We do not use generic or OEM chips that are unreliable. Compatibility: Industry standard memory. Guaranteed 100% compatible. Experience: Memory expert since 1990. Exchanges and Returns: No hassle exchanges and refunds. Shipping: Quick shipping. Shipped in well padded envelope or box with antistatic packing.