Roomba Virtual Wall Mod, for In-wall AC Power (no More Batteries!) : 8 Steps - Instructables
Virtual Wall Dual for Roomba iRobot Virtual Wall
Overview of the Virtual Wall®.
iRobot Roomba Virtual Wall – New Screwdriver
Amazon.com: Rechargeable Dual Model Virtual Wall Barrier Compatible for iRobot Roomba 800 900 I/S/E Series e5 e6 i4 i6 i7 i8 and All Plus Versions S9 : Home & Kitchen