LiftMaster 821LMC Additional Sensor for Smart Garage Control

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Control a second garage door through LiftMaster’s MyQ Smart Garage System with the 821LMC-SENSOR from Action Industries. The 821LMC-SENSOR is an additional sensor that mounts to a garage door to enable smart device control via their 821LMC-S Smart Controller. LiftMasters 821LMC Smart Garage system works with all major brands of garage door operators manufactured after 1993 and allows existing openers to be retrofitted into a smart garage door opener. The 821LMC-S comes with one sensor for single door operation and an extra sensor is required to control a second door. Receive real-time alerts, set up secure in-garage delivery through Key by Amazon, and control your door from anywhere in the world. The 821LMC-SENSOR requires purchase of the Smart Garage Control (Models 821LMB and MYQ-G0401), or Smart Garage Hub 1st generation (Models 821LM and MYQ-G0201). Each sold separately.


  • Add-On sensor for control of a second garage door with LiftMasters Smart Garage Controllers

  • Secure, control, and monitor your second garage through the MyQ App

  • Control your garage with smart devices like Smartphones, Tablets, Computers, as well as traditional controls like keypads and remote controls

  • One sensor required for each door

  • Warranty: 1 year

  • LiftMasters Smart Garage systems work with all major garage operators manufactured after 1993

  • Compatible with LiftMaster Smart Controls: 821LM, 821LMB, and 821LMC

Product Manual

Product Manual

Product Manual