Haven't had problem with it, but seeing no one replied to your question, I'll post this.
Robertshaw Wireless Propane (LP) Gas Tank Level Meter RS-228
For some reason, the RV industry thinks 2/3 full
is a good enough figure to keep everyone at bay. It shows up quite often. Holding tanks and propane tanks alike. I think it has something to do with the fact that RV gages are not being designed by NASA.