Panaracer GravelKing X1 Plus Tire - 650b x 48 Tubeless Folding BlackPanaracer GravelKing X1 Plus Tire 650b x 48 Tubeless Folding Black. Everything that the standard X1 offers but with added protection for those particularly tough rides where there may be a greater risk of punctures. Ideal for gravel dirt and rough pavement TuffTex+ increases tire resilience with a dual layer of bead to bead TuffTex material providing additional puncture resistance and heightened security in the most challenging conditions BeadLock is