STI-8100-BK — Safety Technology International Smoke Detector Damage Stopper, a black polycarbonate protective cover for flush-mounted smoke detectors, supplied with standard mounting hardware.
The Stopper is designed for easy installation in areas prone to vandalism or physical abuse, which can lead to false alarms and high maintenance costs. Made of highly durable polycarbonate, the cover helps assure the smoke detector will be operational when needed, and it is easily removable for servicing the protected detector — loosen the four screws, rotate the cage counter-clockwise and lift it off. The STI-8100-BK is the black version of the clear STI-8100; a white STI-8100-W is also offered. For surface-mounted detectors or installations with conduit, the STI-8101 stackable 2″ polycarbonate spacer is added (the STI-8130 is the factory pairing of cover plus spacer).
Specifications
| Model |
STI-8100-BK — Black, flush mount Smoke Detector Damage Stopper |
| Material |
Polycarbonate |
| Mounting |
Flush mount |
| Dimensions |
8.25 in. H × 8.25 in. W × 3.75 in. D (210 × 210 × 95 mm) |
| Mounting holes |
Four, 3/16″ dia. (4.8 mm), for 19018 anchors |
| Cover mounting screws |
Four #8 × 2 Phillips pan head (included) |
| Listing |
UL listed to US and Canadian safety standards for use with specific smoke detectors |
| Warranty |
Three year guarantee against breakage in normal use |
Installation notes
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Do not paint: painting the cover may obstruct the flow of smoke to the detector.
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Siemens detectors: when installing the STI-8100 guard with Siemens detectors, sensitivity adjustment is mandatory — see the Siemens detector install sheet.
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Code compliance: the installer shall follow NFPA 72 National Fire Alarm Code (protective signalling systems) for installation, testing and maintenance.
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Detector compatibility: the UL listing applies to use with specific smoke detectors — verify your detector model against STI’s listing before installing.
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Unstable surfaces: STI recommends the optional STI-8171 backplate for irregular or unstable mounting surfaces such as drop ceilings and beams; it adds 0.25 in. (6.3 mm) of depth.
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Surface-mount detectors: a flush-mount cover alone will not clear a surface-mounted detector or conduit — add the STI-8101 2″ spacer, or order the STI-8130.
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Tamper resistance: tamper-resistant spanner screws are optional, not included — KIT-81 (#8 × 2″ snake eye, qty 4) for the STI-8100, with KIT-19038 tamper bit.
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Servicing: the cover removes by loosening the four screws and rotating counter-clockwise; the spacer, if used, remains fastened to the mounting surface.
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Proposition 65: STI notes this product can expose you to chemicals including Dichloromethane and Bisphenol A (BPA); see www.P65Warnings.ca.gov.
Related models
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STI-8100 — identical cover in clear polycarbonate.
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STI-8100-W — identical cover in white polycarbonate.
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STI-8130 — clear surface-mount version: one STI-8100 cover plus one STI-8101 spacer with standard mounting hardware.
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STI-8200-SS / STI-8230-SS — 1.2 mm 304 stainless steel flush and surface-mount equivalents for food, water treatment and correctional applications.
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STI-8200-W / STI-8230-W — 1.5 mm coated cold-rolled steel flush and surface-mount equivalents.
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STI-8101 — stackable 2″ polycarbonate conduit spacer; STI-8171 — mounting backplate.
Specifications taken from the Safety Technology International sales data sheet “STI Smoke Detector Damage Stopper — Polycarbonate Protection” (rev. 10/25) and installation sheet “STI-8100/STI-8130 Smoke Detector Damage Stopper,” document 8100IS (Sept 2025). Manufacturer specifications are subject to change without notice.
