This pack of 20 porcelain mortar and pestle sets each have a 2 oz (60mL) capacity. Each mortar measures 3.2 inches wide and 1.9 inches tall with a contoured spout for easy pouring. Each pestle measures 3.8 inches in length with a 1.1-inch diameter rounded grinding end. The inside grinding surfaces are unglazed for precise grinding. The solid porcelain construction is resistant to chips and cracks. The 20-pack format is great for outfitting a classroom. Suitable for finely grinding herbs, spices, seeds, nuts, grains, pigments, powders, and pills.