You are looking at a White Industries ENO hub and wheel designed to fit frames with vertical dropouts...like Cannondale. I used this with my old Cannondale road frame for about 5 years. It worked fantastic. If you don't know, White Industries makes some very nice hubs. Here are the specifics for this wheel:
1. White Industries ENO hub (130 mm, 28 hole).
2. Aluminum aero, 700c rim with 14 gauge SS spokes.
3. Rim tape (Velox).
4. Shimano 17 tooth, single speed freewheel on one side.
5. 18 tooth fixie gear on fixie side.
Just the hub new cost $250. You get the whole wheel with this deal. Email me with questions.