Beddit, the sleep tracking company that Apple bought two years ago, is launching a new beta program to allow customers to test and offer feedback on new features before release. The new Beddit Beta Program is free for participants who enroll, but there are a few requirements for participation.

For starters, participants will need the latest Beddit Sleep Monitor hardware released in December. Apple Stores currently sell the 3.5 model version required for $149.95. Testers also need to live in the United States and agree to only test Beddit in the US, and there’s an age requirement: 22 to 75 years old. Beddit Beta Program participants should also expect to receive occasional email from Apple about the program.

Here’s more from Beddit’s announcement:

Interested customers can enroll at beddit.com/beta using the orange ‘enroll now’ button that opens an email prompt with more details.

Aside from Beddit, Apple offers limited sleep tracking features using the iPhone’s Clock app and Bedtime mode, but more comprehensive sleep tracking apps exist on the Apple Watch. Beddit launched limited sleep tracking on the Apple Watch in late 2015 before being acquired in 2017.

Other sleep tracking apps work well on the Apple Watch and also integrate with Apple’s Health app for viewing sleep duration and more, including these:

  • AutoSleep
  • Pillow
  • Sleep++
  • Sleep Cycle
  • SleepWatch

For more on sleep tracking using the Apple Watch, check out our guide for taming the Apple Watch overnight. Apple is also rumored to be working on built-in sleep tracking with the Apple Watch as soon as next fall, but that feature isn’t expected to work with existing watch models.