The Costway 66 Lbs Fitness Dumbbell Weight Set is designed for versatile strength training, allowing you to freely adjust the weights to suit your fitness needs. This set not only helps strengthen arm muscles and enhance shoulder lines for a healthier physique but also features a connecting option to transform the dumbbells into a barbell. Crafted with durable weight plates made of HDPE and concrete, the set guarantees a solid workout experience. The electroplated hollowed iron dumbbell rods resist rust and wear, ensuring longevity. With an ergonomic handle for a comfortable grip and four threaded collars for secure weight attachment, this compact set is perfect for any home or office environment, making it an ideal choice for fitness enthusiasts.