First of all, hang the sling on your shoulder, don't tie the hook. Then, turn the cup back and insert it from the back to the front. Make sure the chest is suitable and adjust the length of the shoulder strap appropriately. Underwear extension buckle usually consists of upper and lower parts. The lower segment is fixed on the inner side of the bust, and the upper segment is fixed on the shoulder strap of the bust. The length of the telescopic buckle in the upper section can be adjusted as required to adapt to different sizes of bust. Please note that the length of the next paragraph is fixed and cannot be adjusted.