I am one lucky gal! Just the thing I have always wanted to have to work out those aches and pains, and they are just perfect. I did use a tennis ball which was really hard with no flexibility to get into the deep underlying places that needed a bit of massaging. I now have the perfect set and sizes to accomplish the mission. Thank you so much Santa for this great gift of health, the massage balls will be used daily to keep my aches and pains away from ruining a good day!