Dumbbells are auxiliary equipment for weightlifting and fitness exercises. Smaller than a barbell, it is named dumbbell because there is no sound during practice. The weight specifications of light dumbbells are generally 6 pounds, 8 pounds, 12 pounds and 16 pounds (1 pound equals 0.4536KG), while the weight specifications of heavy dumbbells are 10kg, 15kg, 20KG, 25KG and 30KG. So it is widely accepted.