Very good size
I was having problems with breast cysts and these were perfect size to slip inside of my bra - they work well heated or cold - there are no instructions included for heating, so I did the same as with my other ice packs which can be heated and used boiling water on the stove top. After coming to a full boil, take off the burner, place pack in, and allow to sit for 7 minutes or so if starting with a frozen pack - check and go from there.  I did also re-heat them in the microwave without any problems.
Rating: 4 stars