The metal heart inside makes a noticeable difference compared to plain balls, you actually feel the weight shift as you move around. I wear them during my morning chores and the pelvic workout is real but never uncomfortable.
Adam★★★★★
Wasn't sure about the 3 cm size at first, but insertion is comfortable and the metal core gives a nice weighted feel that I actually notice during the day. The pelvic exercises are way less of a chore now.
Olivia★★★★★
I've been using these for about three weeks and the 3 cm size is perfect for starting pelvic exercises without discomfort. The double ball design makes them easy to insert and remove, and I can actually feel my muscles working after a session.