The CNR or Communications and Network Riser is designed to allow OEM system builders to put in inexpensive modem or network adapters rather then building them directly into the motherboard. The devices never really caught on much and you won't find many adapters that use it - even fewer available retail.
What were you looking to do with it?
------------------------------Gigabyte MA785GM-US2H, AMD Phenom II x2 550 BE (4 cores@3.6GHz), G.Skill 2x2GB DDR2 1066 (820@CL4), Scythe Katana3, Hec 585W, Samsung 2232BW+, WD Caviar Black 1TB SATA, Sea 500GB USB, 12 IDE HDs w/Masscool IDE-SATA Convertors, Ugly Old Case, Win XP 32bit
Reply to mongox