We also had the TST 507 installed yesterday! Since we live about 35 miles from Cumming, GA where their business is located, we drove the Axis to them for advice on whether to go with their flow through or regular sensors. Mike was super helpful and installed the flow through sensors on the RV and recommended the regular 507's for our toad as they are shorter. We decided to buy 2 sets of 6, so we have a spare sensor of each type. He also swapped the extra monitor from the second set for the repeater.
Have read volumes on IRV2 about their great customer service, and we were both impressed with how helpful Mike was! He also answers his phone until midnight 7 days a week, if you need trouble shooting or help while traveling! Can't think of another business that is so available!!!
When you buy from them directly you get a 3 year warranty, and they are currently running a 10% off special if anyone is interested in ordering.
Was great to check all 6 tire pressures and temperatures almost instantly when we were at the motorhome today!! Will try out the toad's sensors next time we hitch up, but based on our return trip yesterday we expect to be equally happy with them!!!