The life maxx fixed dumbbells set with rack comes with commercial grade dumbbells which have extreme durability and strength which make them perfect for a gym or strength training facility these dumbbells are made of solid cast iron making them compact and sleek they are comfortable to lift no matter what weight you are lifting the knurling on these dumbbells is perfect for all users providing a great amount of grip for lat rows and other lifts where you need a good grip key features of the