This is the tire pressure gauge I use in my kart racing career. A tire pressure gauge like this when plugged into the tire displays the air pressure in the tire and is able to take hair out of the tire with the push of a button. In karting tire pressure is important because when the tires get to a certain heat the pressure rises and as the pressure rises the tires start to lose grip. Setting the right tire pressure before a race helps a lot during the race.