This is the PRO PLUS (Pro+) model PowerTap - NOT just the "Pro".
You can remove the wheel and lace up the PowerTap to any wheel you want!
 
The Intersection of Performance and Value. For mid-level riders, the CycleOps PRO+ serves as the perfect tool to improve power and performance so they finish their next ride or season even stronger. Because of ANT+Sport you can use your favorite GPS device in tandem with the PowerTap PRO+.  
 
The Precision of PowerTap, The Flexibility of ANT+Sport.  
 
Data can be the difference between first and second. PowerTap is the precise instrument that gives you access to real-time performance measurement, and is accurate to within +/- 1.5%. Add the PowerAgent software package, and you'll have all the tools you need to guarantee you make the most of your data.  
 
With the flexibility of ANT+ Sport, all Plus-series PowerTaps can be paired with any ANT+Sport device. So, connect your own GPS device to stop estimating and start measuring!  
 
Features:
 
Wireless 2.4 GHz transmission with Ant+Sport
12mm alloy axle
Alloy hubshell
Coded heart rate
Hub weighs 466 grams
WheelBuilder.com custom wheel
Terry Tellus TT 650Cx28 Tire with Tube
 
$300 OBO
 
http://dallas.craigslist.org/mdf/bop/4997392732.html