In the demo I watched at a quilt show, the lady used the Quilter's SlideLock on the ruler to protect herself from a rotary accident. She said demoing and talking wasn't the safest thing when using a cutter. I think she sold more SlideLocks then the ruler. I use the Slidelock for every med to large ruler, and a cut resistant glove for small rulers. I don't understand not using a safety tool when using a rotary cutter.