I have a 2010 Jaguar XFR and I took a picture of one of one of my rear Calipers and would like to know what that piece that I circled in the picture is for.
thanks ahead time!!! Does that piece come with the new pads?

 

Looks like the connector for the brake pad wear sensor. Generally not included with new pads, recommended that you change with the pads. Look around, prices vary wildly.

 

Yep, it's the pad wear sensor.
Attached to the spring clip on the top of the inner RHS pad.
Never included with new pads.
A problematic waste of time IMHO, much better to check your pad wear manually.
Problem is if you completely remove it you will get constant error messages on the dash, the solution is to unplug it from the caliper spring but leave it connected at the other end and zip tie it up out of the way in the wheel well, I did this on all three Jags.
However if it has worn through and triggered the "low pad" warning on the dash this won't work, instead you now need to cut the wires and join them, preferably up by the electrical plug in the top of the wheel well.

 

Bigg Will guided me to R1 concepts for the appropriate brake parts.. i believe these sensors are $15 each. as per other comments, you could at most need one for rear pass side and one for front driver side..

 

The “sensor” is nothing more than a long wire that the rotor cuts into and breaks the eletrical connection when the pad is worn enough.

If you want to bypass them, take the old sensor and cut the old connector off leaving about 2 inches of wire, then strip the insulation back and twist the two wires together and insulate the bare wires. Plug the connector back into the harness in the wheel well.

It will effectively fool the car into believing the pads are always good.

 

Thanks everyone for all the replies, I appreciate it.
Marco