Kai Professional Scissors are designed for use with thicker, more difficult fabrics.
The 7000 series scissors 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 it allows for easier use.