https://www.cnbc.com/2019/01/15/apple-smart-battery-case-iphone-xs-max-xr-release-date.html

Apple just launched three new smart battery cases for its newest iPhones. It's the first time Apple has launched a battery case since the one it first began selling for the iPhone 6/iPhone 6s.

The cases are available in either black or white and can be purchased for the iPhone XS, the iPhone XS Max and the iPhone XR. They add additional battery life, but also make the phone a bit thicker. They also work with wireless chargers, so you can drop them on a charging pad to juice them up instead of plugging them in.