The black piece pops out and is a horrible design for kids. We have owned it for a little over 4 months. My kid is 7 and can be fidgety at times. Honestly he pops it in and out sometimes. So I guess he stretched it out. So at swimming lessons the pebble came out on its own.

As I have seen other reviews, I purchased this for my 9-year-old grandson. The tracker works fine, but the band broke only after 2-3 months. The tracker was also falling out of the bottom portion of the band. I think that Fitbit needs to redesign a band that works for children.

My son is 9 years old and is the size of an 11 year old and it fits great with loads of room. He loves it and loves the compete with us on challenges. Definitely a great buy, we got it the day it released and he's even got in the bath three times with it on and forgot and it still works great!

Great product, tough for the kids. Can keep an eye on how they are going through the app.

This FitBit is great for kids. The strap is very soft, comfortable on the wrist and easily adjustable. The daily challenges and goals are motivating and engaging. The fun clock faces are a nice feature for children.

Fitbit Ace 2 for Kids Review – Hello! My name is Isabel Good. I'm a kid, and I was asked by Craving Tech to use the Fitbit Ace 2 and let you all know what I think about it. So here are my opinions about it. I will tell you all of the functions, flaws and all.

Built with the intention of making sure your young ones are as active as possible, the Fitbit Ace 2 improves on the previous model with a more eye-catching design, better screen and improved water resistance. To top it all off, it's slightly cheaper than the original, too.

Colorful design; Changeable straps; Swim-proof;

Feels a bit cheap; Somewhat expensive; App can be fiddly to set up

Ultimately the Fitbit Ace 2 is a good evolution of the Ace. The new design protects it a little more, waterproofing is an important addition, it's more customisable and easier for younger children to put on and off - but that important sensor module could do with being a little more secure.

Bigger display does more; Adds timer and stopwatch; Waterproofing; Strap easier to undo; Parents stay in control

Battery life should be longer; Not securely fixed into strap

The Fit Ace 2 is an improvement over the original in every way. Its new design is vibrant and fun, not to mention more durable. The addition of a touch screen also makes for a smoother user experience.

Affordable; Vibrant, kid-friendly design; Interchangeable straps; Fairly accurate fitness tracking; Long battery life

No heart rate monitor

The Fitbit Ace 2 doesn't break the mould for what a kids' fitness tracker can do, but unlike its predecessor it puts everything into a more child-proof package. This feels like a tracker built for kids, but also one that has strong core features and the ability to adapt when Ace 2 owners get bored...

Waterproof design; New goal celebrations; More distinctive look