Lava rocks for tent sauna use. Approximately 10 kg Size: Approximately 100-250mm Löyly possible Made in Japan lava rocks. Lava rocks for far-infrared grilling Lava rocks absorb excess oil. Also popular with high-class restaurants and sweet potato vendors. Can also be used with charcoal for BBQ. Of course, can also be used in hot springs. Can be used in saunas, rock baths, and now also called lava baths, and can be used in various situations.