^its some spacers and a chainwheel for the back hum nad it has a little thing that somes down liek a derailuer would and its sping loaded so the chain wont fall off.
that on ebay and i was gonna buy it but it didnt have the spacers and sprocket that goes on the hub
im trying to get one for cheep causeim poor. nad if you look at the thread its "where can i buy a...singulator for cheep" so no shit i woudl need a singulator
where i'm from those go inder the name "no-rallieur"(sp). so maybe try searchin for that/ www.bikeroom.com is an ok site for buyin stuff, but they prob don't have that part, so i'd suggest lookin at pinkbike.com, theres prob 1 in the classifieds there