A variant design uses a wheel-shaped blade mounted on a sliding shuttle attached to a rail. This type of paper cutter is known as a rotary paper cutter. Advantages of this design include being able to make wavy cuts, perforations or just score the paper without cutting, with the use of various circular blades. It is also almost impossible for the user to cut him/herself, except while changing the blade. This makes it safer for home use. Higher-end versions of rotary paper cutters are used for precision paper cutting and are popular for cutting down photographs.