*I noted that some folx are calling these convex point sharpeners. When discussing surfaces the correct term is concave. With a surface, concave means that it bulges or caves inward while a convex surface bulges outward. This feels differently than in math where the look of a concave function bulges upward and a convex functions bulges down. Save your corrections for someone else.
This sharpener was purchased because fans of my reviews smashed that Ko-Fi coffee button on the right sidebar. If you like my reviews consider giving me a bit of that sweet caffeine with a $3 coffee.