Detector bases are injection molded out of ABS material.  Retainers and clips are manufactured out of naval brass (highly resistant to corrosion).  The clip spring and fasteners are brass.

Applications:
Basement Windows, Jalousie Windows and Doors, Air Conditioning, Duct and Vent Openings, False Ceilings, Internal and External Aisleways, Doorways, Overhead Garage Doors and Skylight Hatches.

Features:
Insulated for live or dead installations.  Thespring that is supplied is connected to a zip cord across the opening.  It then becomes part of the protective circuit and is supervised.  Tension adjustable by opening or closing the arms.