I am not sure if this is a radiator fan switch, knock sensor, or a oil pressure sensor and am at a loss. I have a B7 harness and i believe this sensor in the picture below gies to another one above the oil filter that is a single nipple. Just need some help please.
The sensor input on the B2 engine.
My B7 harness. I believe this goes to another sensor nest to the one shown in the picture.

 

The twin male post/bullet connection sensor from your first photo is actually the fan control switch. On your B7 engine, the fan control switch is a two pin round plug found on the thermostat housing near the passenger side rear corner of the block. Using the B7 water pipe and thermostat housing will require no modification to this plug style. Using the B2 parts, you will need to extend this wiring and change to a pair of female bullet connectors to connect to the block mounted fan control switch you photographed in your first picture. The single female bullet connector in the partial rubber hood to photographed in your second pic is the oil pressure sensor for the idiot light on the gauge cluster. This sensor is found in roughly the same position on both blocks.

 

I figured it was a radiator fan switch. As the picture shows below my B7 block that shows the oil pressure sensor but the radiator fan switch is absent due to the fact that they implemented it into the thermostat. Now, my question is: Can I use the B7 thermostat on my B2 block and eliminate the double bullet connector or just leave it there unplugged or is that not possible? My B7 block where the oil pressure sensor is visable but the radiator fan switch that is on the B2 is absent.