Herb grinder
A herb grinder (or simply, a grinder) is a cylindrical device with two halves (top and bottom) that separate and have sharp teeth, blades, or pegs aligned in such a way that when both halves are turned, material inside is shredded. Though the manufacturers claim they are intended for use with herbs and spices for cooking, they are often used to shred cannabis, and are often unsuitable for actual use with spices (which instead are prepared using a burr grinder), resulting in a product that can be more easily hand-rolled into a "joint" that burns more evenly.