Amazon.com - 2-Pack Dual Model Virtual Wall Barrier Compatible with iRobot Roomba 500/600/700/800/900/e/i/s Series Robot Vacuum. Compare to Part 4636429 -
How To Use a Virtual Wall Lighthouse | Roomba® 800 series | iRobot® - YouTube
iRobot Dual-Mode Virtual Wall Barrier for Select Roomba Vacuums 4636429 - Best Buy
Amazon.com - iRobot Roomba Authentic Replacement Parts - Dual Mode Virtual Wall Barrier Compatible with Roomba 600 700 800 900 Series -
Roomba Virtual Wall Barrier Not Working? - (Top Solutions!)