Apple Inc. (AAPL.O) on Tuesday released re-chargeable battery cases for the iPhone XS, XS Max, and XR that add several hours of battery life to the smartphones.

The Cupertino, California-based technology giant previously offered a similar case for its older iPhone 6 and iPhone 7 models. The new cases increase talk time from 20 hours to 33 hours on the iPhone XS, 25 hours to 37 hours on the XS Max, and 25 hours to 39 hours on the XR, according to Apple’s website. The cases can also be re-charged with inductive chargers.

The cases cost US$129 and come in white or black. They’re popular with many iPhone users and contribute to Apple’s Other Products segment, which generated US$4.2 billion in revenue in the fourth quarter, up 31 per cent from a year earlier.