TST 507. One problem, but they handled it well.
The receiver's battery died. Not the replaceable batteries in the senders, the one in the receiver. As long as the receiver was plugged in, it worked fine. Unplug it, no matter how long it had charged, it instantly died.
I called them, and even though it was out of warranty, they mailed me a new receiver. No charge.
This was the same trip where it told me a tire was 160+ degrees. I had a dragging brake. It saved me from a possible RV fire. I was glad I had left it plugged in.