Liftmaster 2 wire fail safe infra-red safety beams can be used with the following control boards: CB11, CB22, CB124, CB24.
They are sold as a pair and the inside electronics and lens can all be twisted 180 degrees. This gives greater movement for ease of installation as photocells can be mounted on un-even walls or at 90 degrees more easily.
Also Known as photocells, these are essential to the safety of your gates, if the beam between the two photocells is broken it means something is in the way that is a car, vehicle , child or pet, so the gates won't open. If the beam is broken when the gates are moving they will immediately stop and reverse.
Liftmaster photocells are fail safe and may not be compatiable with other gate automation systems