Dumbbell sets, a set of about 4 to 6 pairs, but generally buy 1 yes, buy 10 kg. Mainly to save places, you can practice anywhere. Such as big head, biceps, triceps pectoralis, shoulder muscles and back muscles. Generally, the back muscles are the heaviest, and those who exercise more in the gym will now use 15 to 20 kg. The question you should ask is to buy one to play at home, not to exercise professionally. I suggest you buy one 10 kg. One group 12, 4 to 6 groups at a time. The muscles feel sour, and when they swell, you can see that the muscles are red and the blood vessels are intense. In other exercises, such as the above, it is to exercise the shoulder muscles, and stretching is to pull the chest muscles. You'd better read the fitness book, which is full of dumbbells.
Tip: Don't practice blindly, but find the right posture, which will be effective.
Exercise, passion, perseverance!