Replacement Kit: GSTB-R STB-BL Safety Sensor Replacement Kit for Elf/Overhead Garage Door Openers, compatible with for Elf/Overhead Garage Door Openers manufactured after 1993. Creative Design: GSTB-R STB-BL Garage Door Opener Safety Beam Kit with Bracket. The GSTB-R STB-BL safety sensor beam eye emits an invisible beam from inside the garage door, automatically flipping the door open to prevent damage and accidents when an obstruction is detected. Easy Installation: GSTB-R STB-BL Replacement Kit for Elf Garage Door Sensors. you complete installation and use in minutes. Tip: Ensure the garage door opener is not powered on before installing the safety backup sensor. Our Mission: Garage door sensor systems are designed to ensure maximum safety during garage door opener operation, protecting children and pets. Color:Black Material:Plastic + Aluminum Package Contents: 1 set * for Genie Garage Door Sensor