COLONIAL NEEDLE-Rotary Blade Sharpener. Dual rotary blade sharpeners restore a razor-like edge to the blade designed for your rotary cutter. A manual twist of the handle causes abrasion against the sharpening disk which sharpens and smooth's the edge of the blade. This disk lasts up to six months if used daily. Safe, economical and easy-to-use. For use with all brands of rotary blades. Not suitable for decorative edge. Removes small burrs and dull spots from the blade. This package contains one sharpener for any 45mm blade.