Putting cable box in closet (update and need help)

I got the one pictured below.
The transmitter that goes on the box has three different little sensor looking things coming out of the only cord. Do I put just one on the box in the area of the cable box sensor or all three?

I'm testing it out and I have just one of the three on there and the other transmitter is in the bedroom down the hallway. It works but I have to press the button on the remote numerous times before the channel changes.