Road Cycling - DuraAce Chain

Does anyone know how to check if the chain is a genuine copy or a fake? If it doesnt come in the dura ace package does it mean its fake? Some pple said to look for the number 7701 on the chain but then again some sites claim the model number is 7700? which is which and if both exist whats the difference btween them?

The model # could be 7700, 7701, 7703, the fakes look real, the real ones are 6.6mm wide, the fakes are 6.8 mm wide. Nothing shifts like a dura-ace system and the chain width plays a major part in the overall function. Measure it, if it's not 6.6mm wide it's a 9 dollar chain. All shimano parts come packaged in shimano packaging, If it isn't in a box don't buy it.

i just checked and the model is 7700 dunno bout the width though.. but the shifting is ok cant really tell the diff from my last chain....

oh yeah speaking of which ... what is actually the diff between 7700 7701 and 7703 ? Any price or performance diff ?

7701 and it says "dura-ace" stamped on every link. all the pins are indented and there are 2-3 extra special pins to use when breaking the chain.

CN-7700 was the original Dura-Ace/XTR 9-speed chain.
CN-7701 had a redesigned and hardened pin (reinforced connecting pin) to aide in smoother shifting and robustness because I and many others were snapping sideplates on the CN-7700. This seems to be the current available to the public and is the one listed on the Shimano websites.
CN-7702... does it exist? Can't seem to find out if this was ever made.
CN-7703 must be a brand new chain. I'm not sure what improvements were made. It's probably still a 9-speed chain however. The new narrower 10-speed chain is the CN-7800 I believe. I only saw mention of it in an article in CyclingNews about one of the race bikes but there was no detail about it.

hmmmz are the prices between the 7700 and 7701 the same? I just got the the chain and the shop gave me the 7700 instead sux =|

one of the chains is teflon-coated from the factory. i wonder how long this lasts though...