Here we have a Hershey Racing Cassette lockring
. I can only find 2 images of these anywhere on the web, one from here and the other from a Chinese site. Plus I found reference to them in a scan of the 1995 Hershey catalogue at http://mombat.org/MOMBAT/BikeHistoryPages/Hershey.html
. There really can't be too many of these around...
The turquoise anodising is bright (the finish is even too, it's just the lighting in the photo that makes it look variable), has a few very minor marks but good, with clear logo. Ultralight at exactly 5g. Pretty sure this is the 11t version. £20 posted SOLD.