https://www.theverge.com/2017/10/4/16424740/google-pixel-2-xl-esim-technology-project-fi-first-ever

You’ll be able to use Google’s newest smartphones, the Pixel 2 and Pixel 2 XL, without needing to pop in a SIM card, the company announced today. As long as you’re a Project Fi subscriber, Google will use the devices’ built-in eSIMs to authenticate your cellular account. Prior to today, no smartphone has ever used the eSIM standard. The relatively new technology has typically been reserved for LTE-equipped tablets, smartwatches, and other cellular wearables.

“This means you no longer need to go to a store to get a SIM card for wireless service, wait a few days for your card to arrive in the mail, or fumble around with a bent paper clip to coax your SIM card into a tiny slot,” writes Joy Xi, a product manager for Project Fi, in Google’s official blog post on the subject. “Getting wireless service with eSIM is as quick as connecting your phone to Wi-Fi.”