Thank you for sharing this with us, Angie. We're happy you love our iO Ultimate Clean brush and have had good results. If you ever have any questions or would like to share more about your experience with us, please give us a call at 1-800-566-7252, 9 am-6 pm EST, Monday-Friday.

Thank you for writing your review for us, and we’re sorry to hear iO Series Electric Toothbrush Replacement Brush Heads did not fit your toothbrush. The brush head should slide on with a little downward pressure. Please know that our iO Brush Heads are only compatible with Oral-B iO Series Electric Toothbrushes. If you're using the correct brush head and that's not the case, it's possible that some of the plastic from the inside of your old brush head has come loose and stuck to the brush shaft. Sometimes, toothpaste can build up under the brush head and solidify to form a tight bond. Then, when the brush head is ready to be replaced, it can break during removal and leave this piece behind. To fix it, try running the brush’s top section under warm water for at least ten seconds, then see if you can pull the extra piece off. We’d love to gather some additional details so we can further help you and our Quality Team. Please give us a call at (800) 566-7252 to share more.