Stop Flats2 liners are made of durable, lightweight polyurethane and when inserted between the bike tire and tube, they provide a protective layer between road hazards and the inner tube. Stop Flats2 liners are made of durable, lightweight polyurethane and when inserted between the bike tire and tube, they provide a protective layer between road hazards and the inner tube. Weighs less than liquid fills and thorn - resistant tubes Will NOT cause tire or tube damage - or loosen spokes Thorns or glass that may penetrate the tire are blocked from the inner tube Recyclable - Use from bike to bike
