The Kai 7230 is the 9-inch professional scissor, ideal for thicker, more difficult fabrics. The 7000 series scissors, including the 7230, are made of a high carbon, hardened stainless steel. The addition of carbon allows for a steeper cutting angle, giving the scissor a sharper, finer edge. The carbon allows the finer edge to last longer. This gives the 7000 series a better ability to cut thicker fabrics and allow for easier use.