Check the listing for details. MEM2821-256U768D 512MB Memory Cisco 2821 Router ECC DRAM RAM. Condition: New. Listed at 9.99 USD. MEM2821-256U768D 512MB Cisco Router DRAM ECC Memory as per Cisco specifications. Not the cheap and unreliable Non-ECC memory. Also known as MEM2821-512D, MEM2821-256U768D= Buy 2 to make 1GB kit MEM2821-256U1024D Compatible with Cisco Router 2821. 3rd Party. Guaranteed. 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. 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 anti-static packing.