You can freely adjust the weight of the 66 lbs adjustable dumbbell set to meet your different needs. Use our dumbbells to boost your arm muscles and beautify your shoulder lines for a perfect and healthy body. You can also use a connecting option to combine two barbells into a barbell. Durable weight plates are made of HDPE and concrete for a good fitness experience. The dumbbell rod is made of electroplated hollow iron tube and has the characteristics of rust prevention and wear resistance. The handle ensures a comfortable grip and prevents slipping. And compact design does not take up too much space and is suitable for family members. It is your wise choice.