The dumbbells set come with Round Plates 25mm Diameter one set include 0.5kg x4, 1kg X4, 2KG X4, AND TWO 25MM Bars. If you want big biceps and arms, do curls. If you want bigger biceps and arms, do different kinds of curls with our dumbbells and you get the Key features 1. Concentration Curls 2. Preacher Curls 3. Spider Curls 4. Band Curl 5. Cable Curl 6.