(soft music) - Good morning everyone.

While I do the warmup, I'm gonna come around and check your Yondr, so if you could please go ahead, have your Yondr out on your desk.

If you have your pink pass, have your pink pass out.

- [Narrator 6] It might look like ninth grade English teacher, Aura Smithers is checking homework, but she's actually making sure her students' cell phones are locked away.

She's doing a Yondr check and it's part of San Mateo High School's cell phone-free policy, which bans phones throughout the school day, including at lunchtime.

- For a lot of students, and I think a lot of people like we really don't have a place in our day or in our lives that are cell phone free.

And I do think that there's a huge benefit for students, particularly as they are developing and learning to have a space that is cell phone free.

- [Narrator 6] To create this phone-free environment, the school provides each student with a secure magnetic lockable bag called a Yondr pouch.

Students must bring their pouch to school every morning, turn off their phone, place it into the pouch, lock it, and store it away all before the first bell rings.

After their last class, students are free to unlock their pouch, at bases located around the school campus.

- This was something that our educators felt, you know, very strongly about because it affected students, their mental health, social wellbeing, as well as academics.

- [Narrator 6] Principal Yvonne Shiu has overseen San Mateo High School's push for a cell phone free environment since the beginning.

The idea was initially proposed by teachers.

- Back in spring of 2019, there was a school in the East Base that was using Yondrs.

So we sent a small group of teachers over to investigate and kind of see how it worked.

We found that it releases the responsibility of the teacher having to collect phones, return them, and then students become responsible for their own property.

- [Narrator 6] After purchasing the pouches with funds raised by their parent teacher organization, San Mateo High School rolled out their cell phone free policy for the 2019-2020 school year, making them pioneers in their school district.

- Having just to be able to focus specifically on learning, not having to sort of manage students in putting their phones away, I think really helps students focus on learning and what we're doing in the classroom and interacting with each other.

- It kind of helps train us to not be addicted to our phones.

You know, they're gonna be people who either way are gonna be breaking the rules and using their phones during school.

But for the most part, I think that we are now kind of moving away from constantly being glued to our screens as a result of the policy.

- [Narrator 6] Syd is a senior at San Mateo of high school.

He says he had an adjustment period after arriving here from a middle school that had a less restrictive policy.

- Coming into high school, it was a little odd not, you know, being able to scroll through apps whenever you wanted to and like, you know, write down other people's numbers on your phone.

But it's really small things like that that you missed out on.

I'd say that the benefits were a little bit greater and so I think now junior, senior year, I really appreciate it a lot more.

- [Narrator 6] Although the school is cell phone free, there are exceptions for medical and safety reasons, and students can still call their parents from the school's office phone if needed.

The trade off is worth it for students like Lulu.

- San Mateo's a very social school and we're kind of known for that.

And I think the Yondrs play a big role in why we're so social, because people like talk to each other way more.

Forces you to get past the awkward stages of friendships, which is really nice because I could just be on my phone, and hide away from awkward scenarios if I wanted to, but this allows me to step out of my comfort zone.

- [Narrator 6] Syd and Lulu are just two of many students who see the positives of a cell phone free campus, but not all their peers are on board.

Some find loopholes putting them at risk of having their phones confiscated or receiving detention.

- I mean, there's lots of things that students do to try to sort of go around the Yondr program.

They'll put like calculators or deck of cards in the Yondr pouch.

There's like really creative ways that students have to get around the pouch.

I think some kids don't like the control aspect of it, but I think that they do see how they're able to focus more on their learning.

And I've had a lot of kids say that they really like the face-to-face and not having to compete with the phone.

- [Narrator 6] Despite some occasional infractions, San Mateo High School sees its program as a success, and due to the new Phone Free School Act, a law requiring California schools K through 12 to limit student cell phones on campus by July 2026, more policies like San Mateo's are expected to be created.

- I think, you know, with schools that don't have it, it's a big jump and there is leeway in how schools or districts implement their cell phone free environments.

How San Mateo does it works for us.

And so the little that we can do in getting students off their phones during the school day, I think is helpful.

- I can't say for certain in 10 years whether all of us are gonna be less addicted to our phones than we would've been if Yondr wasn't in place.

But I'd say that it could be a helping factor.

- [Narrator] As of June 2025, California is one of four states that has laws in place limiting cell phones in classrooms.

18 other states and Washington DC have banned phones in schools altogether.