Hex Dumbbells are the most popular item in exercise equipment! Designed with a highly durable cast iron, these dumbbells are regarded as the best quality available in the market. Warning: This product contains one or more phthalate chemicals known to the state of California to cause birth defects and other reproductive harm. Consumer may return the product for a full refund, including shipping cost for both receipt and return of the product within 15 days of his or her receipt.