I hard one that I used during the winter with a Power Tap wheel with cadence and speed sensor. I also used it with a Stages Power Crank that is on my track bike. It worked fine when the bike was on a trainer and my iPhone was on the pool table next to me or mounted with a Wahoo case on the bike stem. Once outside when I put the iPhone in my back pocket the RFLK+ head would not transmit/communicate with the iPhone. I called Wahoo several times trying to sort it out with no luck and they offered to take everything back for a refund. Maybe they sorted out that bug.