Google has discontinued the Nest Protect connected smoke detector. In a post on the Google Nest Community Blog, Google has shared that the Nest Protect is no longer being produced

Nest launched the 2nd gen Protect a year before it became part of Google. Like all smoke detectors, the Nest Protect comes with an expiration date. You're supposed to swap them out every 10 years, so some Nest users are already there.

"The Nest Protect has been one of our most beloved devices," said Anish Kattukaran, chief product officer at Google Home & Nest, "And we are excited to be partnering with established industry leaders like First Alert so users can manage more of their safety devices together for a safer and more protected home."