This is the summary of consumer reviews for Fiskars 9521 45mm Contour Rotary Cutter. The BoolPool rating for this product is Very Good, with 4.30 stars, and the price range is $7.18-$18.09.

Fiskars 9521 Contour Rotary Cutter with a 45 mm stainless steel blade is ideal for easy and convenient cutting of layers of papers and/or other materials like fabrics, felt and vinyl. This cutter allows cutting in many directions such as curves, straight lines, swirls and even some slight reverse movements. The rotary blade is easily assembled to either sides of the cutter, thus providing optimal blade visibility for both right and left handed users. High quality blades are sharp and provide good precision than other ordinary rotary blades. For efficient precision cuts, it is good to align the blade guard in the right position with the help of engraved markings. The curved loop handle design gives a natural fit for easy one hand operation thus improving control while adjusting the materials. The cutter also features a sliding button which extends blade during use and locks it into position, and also retracts it for safe storage. Blades snap in and out easily for quick replacement.  

However, many reviewers say that the blades retraction button is poorly made. The sliding button for using and locking the blade trips easily, thus disengaging the blades and giving uneven cutting edges. Many users feel the blades are dull and leave painful hands as it requires hard pressing to cut through couple of layers of fabric.

Overall, the Fiskars 9521 45 mm Contour Rotary Cutter is a perfect and handy accessory for craft enthusiasts. This is recommended tool for quilters and sewers of all levels or even craft projects for its ease of use, precision and affordable price.