Nuetech TUbliss 21& 18 Tubeless Tire System Gen 2 Includes: Qty.1 18 Tubliss System(Fits 18 x 1.85 to 2.15 Rim) Qty.1 21 Tubliss System(Fits 21 x 1.6 Rim) Turns your tire into a tubeless tire Better traction, quicker acceleration, plusher ride Tires last longer No pinch flats 2 minute tire repairs Superior rim protection Lighter than tubes, Weighs 1lb. 12oz Exact item you will receive is pictured Breakthrough Low Pressure Capability Tubliss replaces conventional inner tubes with a small red 100 psi insert that creates two different pressure zones within the tire itself. This enables an incredible 100 psi of rim protection, increased tire stability, and eliminates pinch flats. This allows you to run very low tire pressure for massive gains in traction and a much plusher ride Massive Traction Gains Tubliss allows you to run a much lower tire pressure creating a much larger contacting patch, this equates to instant bolt on performance you can feel and take advantage of on the first ride No Pinch Flats By eliminating the tube you eliminate pinch flats forever 2 Minute Tire Repairs Without the tube you can now plug tires in seconds using standard tubelss tire plugs(no need to remove the wheel), and in the event of major tire damage, Tubliss acts like a full circumfrence rim lock allowing low speed run flat capability Super Durable When properly installed and maintained they can out last the life of your bike, much more economical than buying countless tubes Tires last longer More traction equals less spin and wear, that combined with lower operating temperatures can substantially increase the life of your tire. Majority of tire will perform better, longer, due to added performance of running lower PSI