These excellent tires are longer-wearing than our Pro Compound Slicks, but provide more grip. They come without inner foams so racer can choose the proper foams for the track they are racing on. We suggest our Rounded Pro Molded Inner Foams in either Soft (#4678) or Hard (#4679) compounds. The rounded shape of the tire keeps the tire IFMAR- and EFRA-legal while the contact patch retains the properties of super-narrow tires (22mm). The rounded tire concentrates the weight of the car on a smaller contact patch for better control and acceleration.
The "B" is the letter code for the compound of the rubber used in the tire. The "15-40" refers to the temperature range in Celsius that the tires should be run in. (Fahrenheit conversion is 60-105 degrees)
