Amazon.com - iRobot Self-Charging Home Base 4931 (Compatible with iRobot Dirt Dog, iRobot Roomba 400 Series and Discovery Series) - Robotic Intelligent Vacuums
Roomba 400 (Discovery?) and docking station. • Robot Reviews
Amazon.com: T POWER 22V Charger for IRobot Roomba 400 500 600 660 670 700 760 770 780 790 880, 400, 500, 600, 700, 800 Series Vacuum Cleaner Full Range of Sweeping Machines Ac Dc Adapter Power Supply : Electronics
5-Pack iRobot Roomba 4230 Filter - Replacement for the iRobot Roomba 400 Series Filters - Walmart.com
iRobot Roomba 400 Features | Robot Vacuum Cleaner Reviews