Stopper II® clear polycarbonate cover with a warning horn & French labelling for flush mounted manual pull stations

The industry-standard solution for preventing malicious false alarms.

The Stopper II is a world-renowned protective shield made of heavy-duty polycarbonate, designed to secure manual fire alarm pull stations. This specific model is tailored for French-speaking environments (such as Quebec), featuring silk-screened instructions in French. Its primary function is deterrence: the moment the cover is lifted, a powerful local siren sounds, drawing immediate attention to the person before they can trigger the building's main fire alarm.

This cover is UL listed hence the equipment and its installation meets Canadian standards. It is also FM approved; the Factory Mutual Approvals is a group offering testing and certification services on products for commercial and industrial use. This piece of equipment is ideal for fire safety in public locations such as schools, hospitals, mills, etc.

STI™ product code: STI-1100/FRE

Stopper II® covers protect manual pull stations from impacts and help prevent false fire alarms without restricting legitimate alarms. The cover can easily be lifted and is connected to the frame by a metal cable. It was designed for indoors use only. Such an accessory requires a double action to trigger a fire alarm compared to a simple pull station which requires one sole move.

All labeling on the cover are in French, however, the instructions provided in the package are only available in English (PDF version available for download).

External dimensions:
Length 7 in x Height 10 in x Depth 3.5 in
(Length 17.8 cm x Height 25.4 cm x Depth 8.9 cm)

Inner dimensions:
Length 5.5 in x Height 6 in x Depth 3.25 in
(Length 14 cm x Height 15.24 cm x Depth 8.25 cm) 

Polycarbonate thickness: 0.095 in (2.4 mm)

This cover fits most pull station models, mainly flush mounted ones.

Covers with English labeling are also available when permitted by local regulations (see item ECSTI1100).

Polycarbonate properties:

Polycarbonate is a clear low flammability material highly resistant to impacts which features impressive mechanical and thermal properties, hence its use in so many fields. It is commonly used to manufacture safety eyewear, protective faceshield, law enforcement shield, optical lenses, thermal imaging and so many other vandal-proof items. The polycarbonate used for the fabrication of Stopper II® covers is UV-stabilized against degradation caused by the sun.

Key Benefits: Deterrence and Compliance

• Immediate Sound Deterrent: The integrated siren (95–105 dB) is extremely effective at stopping pranksters or vandals in public spaces before they pull the alarm lever.

• Ultra-Resistant Polycarbonate: Made from a virtually indestructible material, it protects the pull station from physical impacts, stray sports balls, and heavy-duty wear and tear.

• French Language Instructions: Meets specific linguistic and safety requirements with the text: “En cas de feu, soulever le couvercle et tirer la station.”

• Accidental Trigger Prevention: Prevents unintentional activations in narrow corridors, crowded hallways, or gymnasiums.

• Flush-Mount Design: Specifically engineered for pull stations where the electrical box is recessed into the wall.

Technical Specifications

• Material: UV-stabilized, clear polycarbonate (high impact resistance).

• Local Alarm: Piezoelectric horn.

• Power Source: 9V battery included (powers the local siren only).

• Language: French instructions (Red silk-screen).

• Dimensions: Standard size for flush-mount manual stations.

• Certifications: UL/cUL Listed and ADA Compliant.

Application Guide: Where to Install

This device is highly recommended in environments where false alarms are frequent or costly:

1. Schools & Universities: To stop students from pulling alarms before a full building evacuation is triggered.

2. Arenas & Sports Centers: To provide a physical shield against impacts.

3. Hospitals & Care Facilities: To prevent unnecessary panic caused by accidental bumps in high-traffic areas.

4. Shopping Malls: To secure emergency exits and low-supervision zones.

FAQ: Frequently Asked Questions

Does the Stopper II alarm notify the fire department?

No. The Stopper II siren is local only. It serves to alert staff and bystanders that the cover has been opened. The signal to the monitoring station and fire department is only sent if the manual station inside the cover is actually pulled.

How do I silence the siren once the cover is opened?

Simply close the cover back onto its frame. A magnetic or spring-loaded switch automatically resets and silences the siren.

Occupational Health and Safety (OHS) Expert Advice

• Maintenance: It is vital to test the 9V battery during monthly safety inspections. If the battery is dead, the protector loses its primary deterrent function.

• Cleaning: Use only a soft cloth and mild soapy water. Avoid solvent-based cleaners, as they can cloud the polycarbonate and make the instructions difficult to read.

• Compliance: This model is ADA compliant, as it does not protrude more than 4 inches from the wall when installed on a flush-mounted station, ensuring it does not become a hazard for the visually impaired.

Maintenance and life service:

Some basic practices should be adopted to maintain manual pull station covers. It is thus recommended to wash the cover with lukewarm water and a gentle soap; be aware that if one lifts the cover while cleaning, the alarm will go on until the cover is snapped back into place. The manufacturer strongly advises not to use steel pads since they scratch any surface they touch which will temper with the legibility of the label. It also is not recommended to use harsh soaps on the cover since polycarbonate doesn’t mix well at all with a wide array of acids and other chemical compounds. Indeed, these products will make your cover kind of melt. If the cover surface isn’t soft to the touch and bubbles appear, the cover has been corrupted and must be replaced.

As for its life service, the manufacturer asserts that his Stopper II® covers are durable; some have been in service for almost 20 years. Of course, the warning horn and battery should be inspected every 6 months to make sure they function, and the 9-Volt battery should be replaced yearly if need be.

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