These dumbbells incorporate commercial gym durability with comfort and affordability. Dumbbells are used to exercise all major muscle groups including arms chest back abs legs and core. The benefits of dumbbell exercises include muscle building improving core strength boosting balance providing better bone health burning calories increasing energy levels enhancing overall mood and more. Dumbbells are perfect for isolations full body functional and HIIT workouts. The CAP Barbell Coated Dumbbell heads are made from ASTM A48 Class 20 grey iron with a durable coating and joined together by a solid 1018 cold rolled steel chromed handle.