[This review was collected as part of a promotion.] It’s very important brushing your teeth. This is the best toothbrush you can found and the price is really reasonable. Although it has 4 options and I always use the sensitive one .

[This review was collected as part of a promotion.] I love how gentle these are. The fact that these let you know when it’s time to replace them helps especially as a busy mom. I’d recommend these to everybody I know.

[This review was collected as part of a promotion.] So I bought this brush and got the brush heads . The brush heads are great and click on easily so gentle on my teeth and make them so clean. It's a great price for 4 brush heads.

[This review was collected as part of a promotion.] GREAT brush heads. The oral b iO line is one of the best brushes in the market. Does an amazing job of keeping all areas clean and is super gentle! Also easy to switch out and transport.

[This review was collected as part of a promotion.] We love our Oral-B system to clean our teeth. And these ultimate clean head refills are just great. They fit on the toothbrush really well and feel like they clean our teeth really well too.

[This review was collected as part of a promotion.] I like that there are 4 pieces in the package. They change color when you need to change the nozzle. Comfortable to clean. OralB iO Ultimate Clean Refills - Compatible with Oral-B iO Electric

[This review was collected as part of a promotion.] These work great and I love the tooth brush. They don't hurt your teeth and they are very durable and these are a great value can get them and reuse.

[This review was collected as part of a promotion.] I really love Oral-B toothbrushes. Thiis refil is very effective. It lasts long. It cleans very well and is comfortable to use. Also it has high quality.

[This review was collected as part of a promotion.] Simple packaging and easy to use. My teeth felt very clean and I enjoyed the brush on the very first use. Good value for the money. Thank you for allowing me to test!

Really does a great job of cleaning teeth, while being gentle on gums. Question: What is the function of that narrow little slot which is just under the bristles?