I ordered two of these for my van and pop up camper because the cheapest camper model that can control 7 tires is $150 or more. I was pleasantly surprised that this model can drive up to 7 buses and I was able to easily use the three monitors from the second set and study on the first one. It is designed to control two front wheels, four rear wheels for a double rear truck and a spare wheel. I installed my 4 minivan tires on the first screen, 2 trailer tires on the second screen, and my load leveling airbags (with an inflation valve) as spares. I was even able to set separate alarm settings for the camper tires and air balance. Works great for my purposes. At first the sensors are fuzzy, but after a few laps around the block, all of the sensors register and are updated regularly.