These natural lava stones are both porous and abrasive making them perfect for scrubbing rough skin on feet, heels, and elbows. How to Use: Soak feet in the shower or bath for a few minutes until the skin is soft. Wet stone and scrub rough areas for a few minutes with light pressure. Multipurpose: Can be used to remove hair or pills from fabric (gently), and even clean stubborn water rings in your toilet. Approximately 3.9" * 2.8" * 1.2".