Norton IM9 1/2 x 2-1/2 x 11-1/2" Fine Grit India IM313 Replacement Oilstone 320-grit for sharpening and maintaining steel cutting edges Aluminum oxide produces durable, smooth-cutting edges, and is preferred for close tolerances Prefilled with oil to allow lubricant to stay on surface during sharpening 1/2 x 11-1/2 x 2-1/2 inch (H x W x D) size makes this stone suitable for use as a bench sharpener for knives and tools Oilstone is more durable and harder than a waterstone