Yichengjin via Amazon offers the Soufull Professional Knife Sharpener for $15.88. Coupon code "SFKSN001" cuts that price to $11.12. Plus, Prime members bag free shipping. That's tied with our mention from two weeks ago, $33 off, and the lowest price we could find. It features a non-slip base and two stage sharpener. Deal ends December 31.