Take your sharpening anywhere with the ready-to-go Dia-Sharp credit card sized diamond sharpener. Fits easily in pocket or wallet. Comes in convenient vinyl color-coded carry case. Offered in coarse, fine and extra-fine diamond grits. Stone size: 2.5 x .75 inch.Pocket-sized convenienceFine diamond for a razor sharp edgeSharpens knives faster than conventional stones with DMT’s monocrystalline diamond surfaceNo oil is needed-sharpen dry or with waterDurable construction will provide years of consistent performance and reliable serviceWARNING: use of this product can expose you to chemicals including nickel which is known to the State of California to cause cancer. For more information go to www.p65warnings.ca.gov.