Lava rocks for tent sauna use. Approximately 10 kg Size: Approximately 100 to 250 mm If you would like to purchase a larger quantity, please comment. Lava rocks for far-infrared grilling. Lava rocks absorb excess oil. They are popular with high-class restaurants and sweet potato vendors. They can also be used with charcoal for BBQs. Of course, they can also be used in hot springs. They can be used in saunas, rock baths, and now also in lava baths, and are utilized in various settings.