NATURAL LAVA STONES--Each stone is made of natural basalt; basalt has good thermal insulation properties and is very suitable for spa, massage therapy and relaxationPROFESSIONAL--Each piece is finely polished, smooth and textured, comfortable to use; professional quality, escort your healthThe ideal choice to relieve fatigue-deeply relax muscles, help relieve stress and tension, improve blood circulation, and keep you healthyConvenience - 4 massage stones have the same size: 3.14 x 2.36 inches (8 x 6 cm), which fits the palm perfectly and can be used effectivelyFlexible application-massage stones are suitable for neck, face, back, arms, shoulders, legs and feet; suitable for SPA, acupuncture treatment and rehabilitation treatmentProduct Specification:Material: natural lava basaltColour: BlackWeight: 680gDimensions: 2.36" x 3.14" (6 x 8 cm)Quantity: 4 piecesfeature:NATURAL LAVA STONES--Each stone is made of natural basalt; basalt has good thermal insulation properties and is very suitable for spa, massage therapy and relaxation.PROFESSIONAL--Each piece is finely polished, smooth and textured, comfortable to use; professional quality, escort your health.The ideal choice to relieve fatigue-deeply relax muscles, help relieve stress and tension, improve blood circulation, and keep you healthy.Convenience - 4 massage stones have the same size: 3.14 x 2.36 inches (8 x 6 cm), which fits the palm of your hand for effective use.Flexible application-massage stones are suitable for neck, face, back, arms, shoulders, legs and feet; suitable for SPA, acupuncture and rehabilitation therapy.notes:1. Please pay attention to the size; and it is the natural energy of the rock. Some rocks have a little texture on the stone, which is normal.2. When you receive the stone, its surface looks like a layer of gray because it is dry; once the massage oil is applied, their color will become darker.Package includes: 4 massage stones