The Flat Ovular Basalt Stones are the most popular choice of stones used by therapists as not only do they retain heat due to their high polished finish, but they are also the most comfortable and convenient shaped stone to use. The round, elongated shape fits perfectly in the palm of a therapist's hand, ensuring the stone is used efficiently. The rounded, narrower edges can also be used to pressurize and knead particularly tense muscles and areas during treatments. This feature is unique to the Flat Ovular Basalt Stone. The XXX Large Flat Ovular Basalt Stones are mostly used to warm the body before a massage, heating them to 130°F/55℃ to warm areas such as the stomach and haunch and use it as a warm neck pillow.Basalt rock is originally found deep within a volcano where it remains for hundreds of millions of years, gaining all of its natural properties. All Basalt is rich with iron and magnesium, which make this stone very effective in massage treatments. Basalt is excellent for holding heat for long periods of time and has very low radiation which makes this rock a much more healthy and beneficial stone for use. Size: 6" X 3.4" X 1.1". 4 pieces per pack. • To warm the body before a massage, heating them to 130°F/55℃ to warm areas such as the stomach and haunch and use it as a warm neck pillow. • The rounded, narrower edges can also be used to pressurize and knead particularly tense muscles and areas during treatments. • Shaped and polished by traditional handcraft, no wax, dyestuff, chemicals were applied. • 100% Natural Black Basalt; Excellent for holding heat for long periods of time; Rich with iron and magnesium. • Size: 6" X 3.4" X 1.1" ", 4 pieces per pack.