This 2oz bottle of Stan’s No tubes sealant is convenient, pre-filled for one application in a bicycle tire. Easily fits in your backpack or saddle bag. A must have for the repair kit and perfect for any tubeless tire installation. Refillable with Stans No Tubes quart or pint. First, remove the valve core and apply through the open stem of a tubeless tire or inner tube with a removable valve cores. Or remove the tubeless tire and apply directly to the tire.