CushCore 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. FEATURES: The system is designed to be used with tubeless-ready or tubeless converted rims and tires, and is compatible with tubeless tire sealants A specially designed tubeless air valve is included with each insert; allowing air to move through the valve without becoming obstructed by the insert The insert divides the inner volume of the tire in half, maintaining air underneath the tread and the foam insert next to the rim SPECS: 27.5: Fits tire widths 2.1 - 2.6? and rims with internal width 22 - 35mm 27.5+: Fits tire widths 2.6 - 3.0? and rims with internal width 32 - 45mm 29: Fits tire widths 2.1 - 2.6? and rims with internal width 22 - 35mm 29+: Fits tire widths 2.6 - 3.0? and rims with internal width 32 - 45mm MX: Mixed set contains one 29 and 27.5" insert Fits tire widths 2.1 - 2.6" and rims with internal width 22 - 35mm