The internal capacity is: diameter 8.5cm, height 5.2cmSOLID RUSTPROOF MATERIAL: Both pestle and mortar are made of food grade 18/8 stainless steel. Not only are they rustproof, it is also resistant to damage and corrosion by acidic food. Small compact mortar, about the size of the average palm - whereas one could pick it up with one handDURABLE AND STABLE: Made of solid metal, the pestle feels substantial in your hand and the mortar sits securely on your kitchen counter. Padding on the bottom makes it stay put even more.FOOD-SAFE: Because stainless steel does not hold residue or leftover odor, all it takes is a thorough rinsing under the tap to get it ready for next use.MESSY NOT: Translucent lid allows you to gauge your strikes and keeps the contents in the bowl, not over counter top.ALL YOUR GRINDING NEEDS: This grinding setup will accommodate just about anyones grinding needs. From medical pills, to herbs and spices; from the pharmacy to your kitchen.