KENDA 18" x 1.75 SV Pair of Tubes ! Kenda 18" x 1.75 SV Pair of Tubes ! Hard to find size tube for 18" tires!! This is for a Pair of Tubes (X2) ISO Diameter: 355; ISO Width: 45 mm. Valve Length: Short 32-40mm. Removable Valve Core. Tube Compound: Butyl.