SRAM's website says they use "GLEITMO™ lube that protects against dirt and friction"
Here's a couple threads on the topic.
http://archive.mtbr.com/09/0EFDC29C.php
http://www.cyclingforums.com/t100400.html
so I'm not sure which specific one they use, 880? I wonder why they don't offer it for consumer use? Nothing seems to last as long or do as well as the initial factory lube on a new chain.