Function: The security sensor sends an invisible light inside the garage door. Whenever there is an obstacle, the garage door will automatically reverse before causing any damage to prevent accidents Applicable: This safety sensor is applicable to Sears Master Mechanics& (since 1997) Replacement: 041A5034 Replacement of safety sensor: G801CB-P, 2610459, 012381050345, 041A5034 Under what circumstances should it be replaced: 1. There is no obstacle, but the garage door stops backing 2. The green light is on, but the yellow light is not, please replace the sensor 3. In cold weather and strong light, the garage door stops reversing Colour:black Material:plastic Package Contents: 2 x Garage Door Opener 2 x bracket Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.