The Fobo Ultra primary kit was designed for vehicles. While we do have many customers who are successfully using primary kits only on their Caravans or Trailers, what needs to be factored though is the length and amount of interference such as other transmitting or electrical devices and materials used in Caravans, Trailers or even the tow vehicles. We recommend the use of a primary kit for your vehicle and Fobo Ultra Repeater set with sensors which are much more powerful and designed for use with Caravans and trailers.
Can I use the normal Fobo Plus kit with Xtra sensors for caravans and trailer. We do not recommend using these for towing unless it is a very small trailer or van. These kits were not designed for use in this way and are predominantly vehicle only kits.
We we understand many customers don't want to use them on their tow vehicles we have found two main reasons. One is of course cost and the other is when we are told that "oh I can feel it in the car"
The reality is that you can't. Science and real life testing have proved beyond doubt that you cannot feel an imbalance in pressure until there is a significant and dangerous decrease. Usually at least 20 psi. By the time you do "feel it' you are already at significant risk.
This is why the United States, the EU and many other countries have made tyre pressure monitoring systems mandatory in all new vehicles. The US since 2007 and EU since 2014.
We support our customers who for whatever reason only wish to monitor the van/trailer but we cannot guarantee a continuous signal for a primary kit. We have found though that in the cases of very long vans placing the in-car unit at the back of the tow vehicle and turning up the sensitivity to maximum usually produces a good result but again we can offer no guarantees.