Shimano 'Zen' Olympic chain ring 144pcd 52T

Super wide 144pcd, Olympic/World Championship track chainrings from Shimano.
These rare Dura Ace rings are very hard to find, even in Japan. I was lucky to come across a stash of NOS rings earlier in 2009.
46,47,48,49 and 50, 51 and 52T are available. Once these are sold, they will be very tough to find anywhere. They are much lighter than the shape suggests, due to cavities milled out of the back side.
Fits 144 track crank sets, such as Sugino 75, Grand Mighty and Aero Mighty, Suntour Superbe track, Dura Ace 7600, 7710, and Campagnolo pista.