I SENT THE TREADMILL DOCTOR THE PARTS ON MY TREADMILL THAT MIGHT BE BAD, AND THEY HAVE NEVER EMAILED ME BACK AND WILL NOT SEND MY PARTS BACK TO ME. VERY UNPROFESSIONAL IN MY OPINION. DONT SEND THEM ANY PARTS YOU WANT TO GET BACK, CAUSE THEY WILL KEEP THEM!!! read full review »