Dual Mode Replacement Virtual Wall Barrier Compatible with iRobot Roomba 500/600/700/800/900/e/i/s Series Boundary Markers Parts - AliExpress
Amazon.com - Coodss Dual Model Virtual Wall Barrier Compatible with iRobot Roomba 500/600/700/800/900/e/i/s Series Robot Vacuum. Compare to Part 4636429 (Pack 2)