beyerdynamic DT-770 M

It's promised that these headphones will isolate very well. The fact is that they isolate poorly. It's difficult to state hands on that these are specific noise isolating headphones, because they isolate just like any other cheap closed headphone.
The sound is flat. No low end, and poor top end. Just a lot of mid frequencies like the sound you get from cheap and very poor headphones.
The construction are fairly robust, so if your kids need some headphones that can take a beating, these may just be the ones.
If price is an issue, then wait and save your money so you later can buy headphones with better qualities than these. Because I'm sorry to say there is nothing about these that justifies the relatively high price.