Can be frozen to relieve swollen sore engorged breasts OR heated to unclog milk ducts, or mastitis, and help with your let down instantly... I wish I got these sooner, I made 10oz in 10 mins because of these amazing things!!! I suffer sore swollen cracked nipples and breasts and these can also wrap around your pumps whilst pumping, or just around your breasts. I freeze one and heat the other and it’s an absolute life saver!! Comes in a pack of two