SDC 491

Break Glass Emergency Door Release

Reviews (1) | Customer Questions (2)


Less false alarms! Compared to pull stations, this glass break release requires a swing of the aluminum rod to cut the power and unlock the door.

In stock

SKU: 491
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  • Aluminum rod Blue housing with easy to read activation instructions avoids confusion with red fire alarm stations
  • Aluminum rod for striking the glass is included (Not required to break the glass)
  • The SDC 491 may initiate the release of an individual door or all doors on the same circuit
  • 2-SPDT 10 Amp Contacts – 1-SPDT for lock release and 1-SPDT auxiliary contact for remote monitoring, CCTV activation or alarm activation
  • The SDC 491 may be mounted in a 2” deep single gang back box or double gang box with plaster ring cover
  • The SDC 491 may be surface mounted with a 491-BB surface mount back box
  • 2 Replacement glass plates

GoKeyless is a trained and authorized SDC dealer. Sales, service, and support. It's why thousands of clients around the world choose GoKeyless™ for their security and access control needs each year.

The SDC 491 Emergency Door Release Break Glass Station provides immediate unlocking of perimeter doors or interior doors that are equipped with fail-safe electric locks.

The 491’s built in alarm may be used as a local door annunciator. The SDC 491 is specifically designed for emergency door release and may influence the approval of an electric locking system. This type of Emergency Door Release may be preferred over a pull station since greater commitment is required to break the glass.


5.5 (H) x 3.5 (W) x 1.375 (D) in.




Security Door Controls (SDC)


5 Year Manufacturer

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5 out of 5 stars

1 review

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What others are saying

  1. Good emergency accesorie, ideal for rush ambient

    CAMILO DE LEON (verified owner)

    I had bought this item like 30 times, and I´ll continue buying and installing it!!

    (0) (0)

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Customer Questions & Answers

  1. Q Where is it made? answer now
    Asked by HOA security team on July 15, 2021 6:04 PM
    Answered by the admin

    SDC products are primarily manufactured in Camarillo, California. 

  2. Q When glass break is utilized, what is the process to reset it for use again? answer now
    Asked by Leonard Williams on September 23, 2019 3:17 PM
    Answered by the admin

    To reset this device, you will need to remove the uppermost Allen-head screw and replace the broken glass panel with one of the included replacements.

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