Ⅰ. Compatibility: The 41A4373A sensor works with LiftMaster and Chamberlain openers from 1993 to the late '90s and supports various LiftMaster residential and commercial ATS models (provided they are already equipped with sensors). Ⅱ. Upgrade: Made of ABS, the 41A4373A door sensor is tested for durability and reliability. It features a yellow safety label for visibility in industrial settings and has a 30-ft operating range. Ⅲ. Installation: The 41A4373A (infrared eye) safety sensor features a center hole for bolt mounting to a bracket, allowing setup. Note: Turn off the opener's power before installation! Ⅳ. Includes: Each sensor has a green light and center bolt for alignment. The set includes a sender, receiver, wire connectors, no brackets included. Ⅴ. NOTE!: This is a compatible replacement, not original. Names are for reference only. Ⅵ. Color: Black Ⅶ. Material: plastic Ⅷ. Package Contents: 2 * sensor, 1 set * accessories