The HP OfficeJet Pro 8135e/8139e is an inkjet printer that replaces the older HP OfficeJet Pro 8025e. It uses HP 923 cartridges and is only compatible with genuine new or remanufactured HP cartridges. This printer comes with a free three-month subscription to HP's Instant Ink service, which automatically ships new ink to your door when it detects it's running low. That said, subscribing to this service requires you to ensure that the printer is always connected to the internet to function. It offers a wide variety of connectivity options, including USB, Wi-Fi, or Ethernet, and there's also support for Apple AirPrint and Mopria Print Service. Its 8.5" x 11" flatbed scanner has an automatic document feeder to scan multi-page documents more efficiently, but unfortunately, it doesn't support duplex scanning.