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
iRobot Roomba*Auto Virtual Wall with Halo sleeve *Protect your delicate areas!* | eBay
Best Buy: iRobot Virtual Wall Halo and Auto On Virtual Wall Black 4319194
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