The ceramic mortar has fine grooves inside to make grinding with the wood pestle easy and nearly effortless.
Comes in two different sizes:
5 inches in diameter, #190001 ($14.95), with one 4-3/4 inches long wood pestle (#497084),
7-3/8 inches in diameter, #190003 ($22.95), with one 7 inches long wood pestle (#497085).
Made in Japan
Click on picture to see detail.