The dualscan microchip cat flap from sureflap has a double antenna which reads your pets microchip or collar tag in either direction it is ideal for multi pet households as it allows you to set different rules for each pet stopping pets which must stay indoors from going outside whilst allowing others to exit it also prevents stray cats and other unwelcome visitors from coming in to your home only unlocking for the unique microchip identification numbers that it recognises the clever desi