Panaracer: Gravel and dirt. Rough and smooth pavement. The most durble version of the “GravelKing” series The strongest version of GravelKing now has even better puncture resistance, with the use of ProTite Shield Plus for withstanding tough conditions. Developed with ZSG compound to enhance durability and wear resistance. Lightweight, ultra-thin 'Ax-Alpha Cord' has been used to make it even lighter in weight.