When shopping for a grinder, you should put a premium on quality, efficiency, and cutting-edge technology when making a choice. With this in mind, this grinder from Cali Crusher should be at the top of the list. These grinders go through a rigorous production process here in the USA that provides durability without sacrificing functionality. Cali Crushers are crafted from a single piece of high grade CNC aluminum. They are scratch resistant through a protective coating created by a procedure called anodizing. This 4 piece herb grinder distinguishes itself from others by using diamond shaped teeth instead of sharp ones. This allows for a consistent grind with every use, the grinder won't dull from metal fatigue, and you run no risk of getting unhealthy aluminum flakes in your smoking blend. The bottom piece of the grinder is an herb chamber that contains a precisely woven non-fraying stainless steel screen. This 4 piece dry herb and tobacco grinder by Cali Crusher has all of the latest technological advances that make it durable, effective, and a must have accessory for any smoking connoisseur.