100% natural nail brush and pumice stone in one. Nail brush with sisal bristles and pumice stone insert made from volcanic rock. The brush part consists of sisal bristles. Sisal bristles are durable, strong plant fibres. The pumice stone is made from volcanic rock. Use: Moisten the area to be treated and the pumice stone. Always use when wet. It wears slowly, so it can be used for a long time.