Signals Defense is a U.S.-based company that makes products to protect sensitive information from electronic spying. The company specializes in blocking radio-frequency (RF) and infrared (IR) signals that can be used to eavesdrop on conversations or steal data. Signals Defense was founded in 1999 and is headquartered in Owings Mills, Maryland. It is best known for its clear RF/IR window films that help secure government and commercial buildings without blocking natural light.

Signals Defense works with highly secure spaces such as SCIFs (Sensitive Compartmented Information Facilities), conference rooms, data centers, and other areas where private or classified information is discussed. These spaces require strong protection because data can leak through wireless or electronic signals. Signals Defense products are designed to meet strict U.S. government and Department of Defense security standards, including TEMPEST requirements that control the release of RF and IR signals.

The company offers a wide range of security products. These include RF and IR shielding window films, conductive paints, foils, tapes, caulks, laminated glass systems, and special window treatments. Together, these products help block wireless signals, stop infrared laser eavesdropping, reduce electrical interference, and improve overall building security. Many of these solutions provide strong protection without changing how a building looks or reducing visible light.

Signals Defense products are used in thousands of secure locations worldwide. Customers include government agencies, defense organizations, and large commercial companies. In addition to making products, Signals Defense also offers technical support and consulting. The company helps architects, security teams, and contractors choose the right shielding solutions and install them correctly in both new buildings and existing spaces.

In 2025, Signals Defense became part of Lockmasters, Inc. This expanded the company’s resources while allowing it to continue focusing on its main goal: protecting people, buildings, and information from modern electronic threats.

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