I'm not sure of the exact frequency of use, but I haven't used it in the last 20 years and it's been stored away, so I don't think it's been used much. It features a reddish-brown earthen texture and a green glaze on the rim of the lid. I can't identify the specific type of ware. It's likely Tokoname ware or Banko ware, both famous for their yakishime (unglazed stoneware). Approximately 200ml. Yakishime kyusu (teapots) are ceramic teapots (mainly Tokoname ware and Banko ware) fired at high temperatures without glaze. They are characterized by the fine pores on the surface that absorb the bitterness of the tea leaves, making the tea smoother and more delicious. There's the pleasure of "growing" it, as the luster increases with use, and the subdued texture is popular. Rich in Iron: Many yakishime kyusu (especially Shudei and Kurodei) are made from clay rich in iron, which further enhances the flavor of the tea. Durability: Because they are thoroughly fired at high temperatures, they are as hard as porcelain and easy to use in daily life. Thank you for viewing.