Spyderco 303MF 1" by 5" DoubleStuff Sharpening Stone - Medium & Fine Sided and Includes Protective Case - 303MF

This is my first traditional ceramic sharpener and I have to say I'm impressed. I own numerous other sharpening media including DMT diamonds, glass-based ceramics (expensive water stones affixed to a glass base), Arkansas stones, oil stones, as well as Japanese water stones, but none compare to the portability of this stone and its ease of use. Oh, and did I mention it rarely needs cleaning and never needs flattening?I was a little concerned about the width of the stone as I'd always brought the tool to be sharpened to the stone and at 1" wide I figured I'd have to skew whatever required sharpening so that it wouldn't hang over the edge of the stone. Simple fix: Bring the stone to the tool, which ended up simplifying the sharpening process considerably especially for penknives and kitchen knives. The medium grit feels abrasive to the touch and does a nice job of restoring the bevel on a dull blade, while the fine grit is as smooth as a baby's backside and produces a stunning hone. However, if you have a severely damaged tool and need to reset the primary bevel I'd suggest something more abrasive than the medium grit unless you have a lot of patience and a great deal of free time.A nice bonus is the leather pouch, which is not the smooth leather as shown in the photograph but the rougher variety; exactly the type that takes honing/buffing compound and allows you to strop a 'wicked sharp' edge on whatever you're sharpening (keep the stone in the pouch, apply the compound, then strop to your heart's content.)Overall a superior quality tool that's an all-in-one sharpener that even provides a means for stropping if you don't mind one of the surfaces of the pouch getting a little beaten up and soiled with honing compound. Oh, and did I mention it rarely needs cleaning and never needs flattening?

These are the same stones that are used in the Spyderco Sharp Maker sharpening system, which I own. One side is the grey medium grit stone and the other is the white fine grit. These are flat stone that are meant to be held in your hand and used to polish out any nicks on your blade. the size makes it easy to toss this in a pocket or a pack to take care of your cutting edge on the go. this stone is big enough to use as a small bench stone, but it is thin so you will need to place it on the edge of a block to be able to work the knife on the stone, but it is also small enough to use as a file on the edge of a larger blade. this is not for the beginner to knife sharpening because there isn't any angle guides or instructions that come with this. It is just a double sided stone and a leather case, plain and simple.Care instructions are wash the stones in warm water with a mildly abrasive cleaner, and air dry. this only needs to be done when the metal particles have built up on the stone that it isn't removing much of the blade material when being used. they are made from ceramic, so they will chip easily, so keep them in the storage case when they are not in use.Not that it matters, but the leather case that came with my stone was a much darker brown and is more of a suede style leather.

The stone is ~1" wide ~5" long and ~1/4" thick (25 mm x 6 mm x 126 mm). It is white on the fine side and dark brown on the "rough" side. The edges are beveled all around. The two pieces of stones are likely glued together. The soft case is a brown suede leather with the Spyderco logo on one side. The stone fits well in the case.I got it as a 1st step to hone chip carving knifes, I find the suede leather case works as a strop, the last step is new paper polishing. My knifes glides through wood (basswood and mahogany). I also used the stone to sharpen my flat chisels for cleaning up oak cuts.I see two advantages of this stone: 1) it is used dried therefore no mess (ie no oil, no water). Debris do build up on the stone over time, cleaning up involves a quick rinse with something like Ajax, water, and a scrubber. 2) It does not need to be flattened. I have heard that ceramic stones never wear down (ie cup), though logically it must wear down with use, so the wear is probably unnoticeable.The thickness makes the stone feel delicate, I worry about breaking it when it is held in my hand and pressure is applied while sharpening, so I usually lay the stone on a flat surface so the entire underside is supported (use the case to increase grip). I think it should be thicker, or something should be glued between the stones to increase the heft. This is the only reason I give it 4 stars.This stone is easy to use and works well. I may switch over to ceramic stones completely.

I really like this. I use a Spyderco Sharpmaker for most routine sharpening, sometimes DMT diamond bench stones for reprofiling a blade. But I sometimes just want to sit down and leisurely sharpen a knife while watching TV or listening to music and the Sharpmaker and bench stones aren't really geared to this type of sharpening. Enter the Double Stuff. It's a Spyderco medium ceramic stone and a fine ceramic stone glued together and stored in a suede leather pouch (I've read that the pouches vary, some being soft suede while some are standard leather). Being 5" in length, it's long enough to hold in your hand while using. I've sharpened up to 4" blades easily. Probably not the best choice for your 16" machete, but it's fine for a large folding knife.It works great as long as you know how to free hand sharpen. Cleaning is a breeze, just like the Spyderco Sharpmaker ceramic rods. Any abrasive cleaner like Comet or Bar Keeper's Friend will work. It helps to use a Scotchbright pad. Sprinkle it on the pad, scrub lightly, rinse off and towel dry. You can also just wipe off the metal residue with a dry tissue or cloth while sharpening to extend time between cleanings. The stone is small enough to carry in a large pocket or pack for touch ups while in the field. It doesn't take the place of a sharpening system or bench stones but it's a convenient and handy addition for anyone who can free hand sharpen.