What is the sensor that is located on the wheel hub, held in by two 10mm bolts, and is activated by every notch on the cv halfshaft?

The line is very thick and runs upwards until it enters the engine bay. I know it is used for sensing either wheel spin for ABS or for wheel speed for the speedometer. My friend snapped the top of the connector off of his today and I was wondering just what exactly does this thing operate?

 

abs

 

That would be your ABS, my firend...Go to your local junk yard and get one.