The tubes have a 3.5 mm outside diameter & 6mm long which is twice as long as standard micro ring, this extra length means that they can keep your extensions in for longer. They also have a lip at the end for easy insertion of an extension tip. The Micro tubes do not break hair or pull own hair out. They are very light and attached strands do not look big. They close flat and nobody can see your extensions.This tubes method is also attached with a needle and pliers, same step as when you use micro rings. It is so easy to close and easy to open. Needle and pliers are also available on request.