CushCore Gravel/CX Tire Insert - 700c x 33-46mm, SingleCushCore is an engineered foam insert to be mounted inside a tire, designed to absorb impacts, reduce vibration and increase lateral stability. These characteristics translate to a more controlled, comfortable, and faster ride. An ultra lightweight insert that reduces fatigue, improves cornering, and helps prevent flats Designed for Tire Widths: 33mm 46mm Fits Inner Rim Widths: 19mm 26mm Note: For 650b or 700c Gravel wheels with a 47c tire or wider