This is a double sided leather strop measuring 8" x 3.5" x .5". There's a piece of vegetable tanned tooling leather mounted on each side of the wood block. Fine (green) polishing compound (6000 grit) added on one side.
Use a leather strop after sharpening your knifewith a stone or grinder to get it to get that ultra sharp, polished edge. You can also use a leather strop regularly to maintain the edge on your knife so you don't have to take it to the stone as often. Start with the side with the polishing compound and then work on the bare side.