TechRabbit has the Scosche Rhythm Bluetooth Cycling Speed and Cadence Sensor in black, model no. BLESCAD, for $14.99 with Free Shipping for a limited time.

The Scosche Bluetooth Smart Cycling Speed Cadence Sensor tracks all your essential biking statistics. Lightweight and wireless, this sensor syncs with your iPhone with a free application! If you’re an avid bicyclist or a beginner, this tool may be just the thing you need to step your game up!