Rock-N-Roller R10WHL/RT/O Replacement No-Flat R-Trac Wheel with Offset Hub (for R10, R11G, R12, and R18 Multi-Carts), 10" x 3" R-Trac tires ride smoothly with excellent traction, like pneumatic tires without the hassle of upkeep or repair R-Trac wheels are also 30% lighter than typical wheels Has a soft cushion ride, low rolling resistance, and high strength polymer hub Fits cart models R10, R11G, R12 & R18