Panaracer GravelKing SK Plus Tire - 650b x 48 / 27.5 x 1.90 Tubeless Folding BLKZSG GRAVEL compound Featuring a specialized gravel specific compound crafted from our proprietary ZSG (Zero Slip Grip) material. ZSG ensures remarkable resistance to temperature and weather fluctuations, ensuring consistent rubber performance across a spectrum from near freezing to scorching temperatures. performs lower Rolling Resistance and Grip for bothGravel and Tarmac. TuffTex + Increases resilience with a dual layer of bead to bead TuffTex