I looked at the TST System. Initially I was going to buy it. Then I saw the Tire-Safeguard System. It does pressure and temp like the TST, but you don't need to have a repeater for large coaches because their signal strenght can go over 120'. Their sensors have a battery life from 6-8 years and as I mentioned the sensors have a air vavle in them. They also have a 2 year warranty. The company that makes them, HCI, has been around since 1994. I think that TST is only a few years old. I maybe wrong with that. Check them out on he web.