This Martelli Ergo 2000 Rotary Cutter 45mm is handy for a variety of tasks. It can cut up to fifteen layers at a time without stress on your hand and wrist. The Martelli rotary cutter has an ergonomic design that is easy to hold. It is helpful for those who suffer from arthritis, carpel tunnel or tendonitis. This hand rotary cutter has a spring-loaded guard and the blades are easy to replace.