Disney MagicBand+ are useful for kids signing into the Oceaneer’s Club and for accessing your room. Bands all come in the same standard length. There are not separate adult and child sizes. Instead, they are designed to be adjustable so they can fit a wide range of wrist sizes.
One side of the band is perforated and meant to be shortened. For kids or anyone with a smaller wrist, you can simply remove the extra section along the perforation to make the band shorter. Once that piece is removed, the MagicBand fits much more comfortably on smaller wrists.
This design makes MagicBand+ easy to use for both adults and children without having to choose a specific size at purchase. Just be sure to adjust it before wearing, since the removed section cannot be reattached later.