The methods of practicing double-door refrigerator are: deltoid front bundle, deltoid middle bundle and deltoid back bundle. Practice twice a week, and do 3 to 5 groups for each movement, with each group ranging from 12 to 15. If you persist for 6 weeks, you can obviously see the changes in your shoulders. According to relevant information: "Two-door refrigerator" refers to a male character with a surprising proportion and a small head and wide shoulders in Korean comics, which seems to be a two-door refrigerator.