Amazon has Sumyth knife sharpener for stainless steel & ceramic knives for $6.19. Just use coupon code: 4KPN96RP at the checkout. The discount price is only $6.19 (Original price: $8.84 now). Limited time deal! The coupon will expire on 2019-01-22.

www.amazon.com/HDS-TEK-Soft-Grip-Professional-Sharpening-Ergonomically/dp/B00Q2CKQHW