Article 75F of the Sporting Regulations says the only type of heating devices allowed for tires are blankets which use "restrictive heating elements". FIA technical delegate Charlie Whiting gave the device the all clear following a recent inspection, saying that the box is simply a different type of "blanket" and that the same, legal restrictive heating element is used.
The metal box can hold a tire without it touching the sides or bottom. The inside of the unit houses the same kind of electrical heating element found in the regulation tire heating blankets that all teams employ. Since the tire is suspended within the box, the air surrounding the rubber is allowed to be heated and the heat is more constant over the entire surface, an advantage over the heating blankets.
As well, the tire rims are also heated which helps to keep the tires at temperature much longer when pulled out of the box. In light of FIA's approval, several of Ferrari's rival teams are also examining different types of "blankets" for their tires.