Work Sharp Folding Field Sharpener Despite its small size, the new sharpener is more versatile than you might expect. The inside of one of its two folding arms features a 400-grit diamond plate with ...

Price Work Sharp lists this sharpener on their website for $300, but I found it on Amazon for $250. Either way, this sharpener is an investment.

Meanwhile, the Work Sharp has magnets on all four sides devoted to four angles (15, 17, 20, and 25 degrees). To keep a knife steady, the magnets have to be really strong.