Dumbbells are small weights. You purchase dumbbells in different weights, starting with lightweight versions -- less than five pounds -- to use during aerobic workouts or while using a treadmill or exercise bike. Heavy Dumbbells are inexpensive, versatile and easy-to-use weights that let you create a variety of workouts to improve your health. Depending on the amount of weight you use, number of repetitions you do and pace at which you use them, dumbbells can help you improve cardiovascular fitness, burn calories, build muscle or increase muscular endurance for sports.
NOTE: 2kg at the right hand side and 2kg at the left hand side, make a total of 4kg.