iRobot Roomba i7 vs Roomba i7+: What's the main Difference?
iRobot Roomba i7+ Review | Reviews by Wirecutter
iRobot Roomba i7+ Review | Reviews by Wirecutter
Review of the Self-Cleaning Roomba i7+ vs Roomba i7: Pros and Cons – Nootrix Robotics
Roomba i7 vs. Roomba 980 (981) | Differences? - Top-VS.com
Amazon.com - iRobot Roomba i7+ (7550) Robot Vacuum with Automatic Dirt Disposal - Empties Itself for up to 60 days, Wi-Fi Connected, Smart Mapping, Works with Alexa, Ideal for Pet Hair, Carpets,