Construction: Lightweight aerospace anodized aluminum alloy Out of the conventional grinders, the most convenient is perhaps those made up of three different pieces. These grinders have a top or lid, a storage area for ground herb, and a bottom or collection chamber for kief. These three pieces can combine with other 3-piece grinders to make a double chamber grinder, separating the ground and unground material for ease and convenience. The 3-piece grinder is perhaps the minimum you should get. Even if you’re used to those pesky 2-piece grinders, this option makes up with better consistency and ease of use, as you will get everything out neatly from the collection chamber and onto your paper. These 3-piece grinders are ideal for anyone that wants a more compact option and who desires to separate their ground flower from kief in two separate storage compartments.