The Crescent Basalt Stone perfectly fits the shape of leg, calf, thigh area, whether the client is laying face up or face down. It is popularly used to apply pressure to muscles, releasing tension throughout the massage treatment. 100% Natural Black Basalt; Excellent for holding heat for long periods of time;Rich with iron and magnesium. Shaped and polished by traditional handcraft, no wax, dyestuff, chemicals were applied. Size: 5" x 2.5" x 1", 2 Pieces per Box.