Vittoria Mountain Bike Air-Liner Tire Insert

Features: 

• Increases control, durability, performance
• Protects the tire and wheel
• Prevents burping and bead breaking
• Compatible with any wheel size (up to 29"), any tubeless valves, and tire widths from 1.9"-4.0"

Specs: 

• Material: Closed-Cell Polymer Foam
• Sizes: Small - 1.9-2.25",  Medium 2.3-2.5",  Large - 2.6-2.7",  X-Large - 2.8-4.0" 
• Lifespan: 2000 hours of normal riding, or 1 full hour of run-flat downhill use
• Weight: Small - 90g,  Medium - 165g,  Large - 200g,  X-Large - 234g