I have an O'lipfa 22' Safety Shield on my 6x24" ruler. It has an adhesive tape that really stays on and it works great just don't place it too close to the edge so that the knob of the cutter hits it. Had a customer come in and complain that her shield was always in the way.. I have had mine shield on that ruler for over 15 years. I don't need a shield on my small rulers I place Omigrid "invisiGrip" and they don't slide. We tried those grippers when I worked at the quilt store but the ladies cutting did not like them and that is when I placed the Safety Shield on the ruler.