"I2CLF" sounds like an in-house (roboticsconnection) name for an I2C Line Follower rather than being a part number. Can you find any labelling, brand or numbers on the device itself?
Are you "Goupil Neutre" who asked about a pc-67-4 line following sensor from roboticsconnection on mbed.org a couple of days ago? If so, is this the same device?