Rena Germany Knife Sharpening Rod - Stainless Steel Knife Sharpener - Knife Sharpener Stone - Serrated Knife Sharpener Stick (8 inch) Size:8 IN   Blade made from Magnetic St Steel AISI 420J2 grade Stainless Steel material. Designed and built exclusively for the tough day-to-day demands of the commercial and home kitchen.