Non-polarized (so you can't hook them up backwards).
The universal sensor works with all major brands of garage door openers - Chamberlain, Liftmaster, Craftsman, Overhead (1995 and up), Genie (2 Wire Systems 1995 and up), Challenger, Stanley, Linear, Moore-O-Matic and Raynor models (built by Chamberlain).
The Universal Replacement Beam Sensor Kit includes:
One Sender and One Receiver Module, Two Mounting Brackets, Four Wood Screws, Instruction Sheet
Made by Digicode these universal safety beam eye sensors work with any garage door opener system that PREVIOUSLY had safety beam eyes.