On the heels of announcing the new Echo Dot Kids Edition, Amazon has a new offering tailored to parents who want more convenient, kid-friendly content for their family. The company now offers Prime Book Box, a curated box of two or four children's books available for Prime members for $22.99.

If you've dabbled in subscription boxes before, you'll know how the Prime Book Box works. Prime members who sign up for the new offering will get a box of books shipped to their home every one, two, or three months. Parents indicate the age range of their children to get books that best suit their reading levels—infants and kids up to two years old get four board books, while all other kids from ages three to 12 get two hardcover titles.

The Prime Book Box doesn't follow rules as strict as some other book subscription boxes. In addition to choosing the frequency of the box, parents can also skip a box whenever they want and choose from a selection of four alternative books if they don't want one of the books that Amazon selects for their box by default. Amazon curates everything, including the alternative book options, so parents can't get any book they want, but that's still a good option to have in case they already own a selected title.

The $22.99 price is also somewhat flexible. According to Amazon's FAQ page, if the books in your box cost less than $22.99 if you were to buy them yourself, Amazon will charge you the lower price. The $22.99 price tag is already more affordable than some other children's book subscription boxes, including OwlCrate Jr. and Reading Bug Box, so it will likely tempt some parents who want a constant stream of new books in the house for their kids to read.

Prime Book Box is the latest push from Amazon into children's content. The company announced the upcoming Echo Dot Kids Edition last week, which features a kid-proof case and a one-year subscription to Amazon FreeTime Unlimited. The company's FreeTime service gives parents and kids age-appropriate content that kids can access through Alexa on the Echo Dot Kids Edition, including educational games and read-aloud stories made by Disney, National Geographic, and other partners.

Not only is Prime Book box a way for Amazon to get back to its book-selling roots, but it's also a way for the company to reach parents who don't want their kids calling on Alexa for everything. There has been growing concern about technology's effect on children and the propensity for kids to get hooked on new tech. Prime Book Box gives Amazon a way to reach parents who prefer their children read physical books rather than asking Alexa to read a story for them.

The new subscription box offering also comes shortly after Amazon announced a price increase for Prime memberships—up from $99 to $119 annually. The company cited new Prime features and increased costs as the reasons it will raise the annual Prime fee starting May 11, 2018 for new members and June 16, 2018 for existing members.

Prime Book Box is currently only available to Prime members, and those interested must "request an invitation" on the Prime Book Box webpage. There's no word whether the subscription box will ever be made available for non-Prime members.