Nuetech TUbliss 21" + 18" MX Tubeless Tire System Gen 2 NEW NUETECH GEN.2 TUBLISS TIRE SYSTEM. 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) - Qty. 1 Turns your tire into a tubeless tire. Better traction, quicker acceleration, plusher ride