About No Tubes Stan's Tubeless System: Converts non-tubeless wheelset to tubeless allowing the use of either standard or tubeless tires. Stan's Tire and Rim Sealant greatly reduces flats, usually lasts from three weeks to three months, leaves no mess in the tire. Patented Sealing Strip can be removed as easily as a tube and used repeatedly. Removeable Presta valve core allows adding sealant without removing the tire (2oz injector bottle sold separately #SX-8054). Can still use a conventional tube in the unlikely event you get a flat. Includes 2 tubeless sealing strips with removable valve cores, 16oz of sealant, 60g scoop, 1 ten yard roll of spoke tape, decal, instructions. Optional: use 1-3 layers of 17mm Velox rim tape centered in the rim, with Stans Sealing Strip on top. When the tire inflates it will snap down in the channel on either side of the tape to improve tire seal. 56 grams per wheel.