The triangular ceramic replacement blades for the Smith's Ceramic Edge Pro Electric Knife Sharpener (item #50349 / 50090).
Replacement Instructions: Remove the Phillips head screw(s) and cover over the blades. Save for re-assembly. Remove the existing carbide blades and discard. Insert new carbide blades with sharp edge of grind facing into v-slot. This applies on both sides. Replace the cover and Phillips head screw(s). Tighten screw(s).