The LiftMaster 041A4373ATS ATS Safety Sensor Kit is a genuine replacement set of photoelectric safety reversing sensors designed for operators equipped with LiftMaster’s The Protector System. These door safety eyes monitor the door opening with an infrared beam; if the beam is obstructed while the door is closing, the operator stops and reverses to help prevent injury or property damage. The kit is intended for use on compatible LiftMaster garage door openers and ATS series light‑duty commercial operators manufactured from 1993 to present that support safety sensors. Each sensor includes an LED status indicator to simplify alignment and diagnostics: a powered sending unit and a receiving unit that confirms beam alignment when properly aimed across the doorway.
This replacement safety sensor kit is suited for residential garage doors and light commercial sectional doors where UL 325 compliant entrapment protection is required. Installation typically mounts one sensor on each side of the door opening near the floor, with low‑voltage wiring run back to the operator’s sensor terminals as directed in the opener’s manual. Correct alignment is essential—solid indicator lights confirm proper operation—and the sensors require a clear, unobstructed line of sight. Use only with LiftMaster operators specified to accept The Protector System sensors; verify compatibility by checking the opener’s model and year of manufacture or the parts list in the owner’s manual. Improper wiring or misalignment can prevent the door from closing, so follow LiftMaster’s installation and safety instructions closely.