Stopper II® clear polycarbonate cover without horn, but with French labelling for surface mounted manual pull stations

Stopper II Cover – Heavy-Duty Protection without Alarm (Surface Mount)

This Stopper II model is specifically designed for manual fire alarm pull stations that are surface-mounted (installed on electrical boxes projecting from the wall). It includes a specialized conduit spacer (deep frame) to accommodate the depth of the station. Unlike models equipped with sirens, this version is silent, relying on the extreme durability of polycarbonate to prevent mechanical damage and accidental activations.

This cover is UL listed hence the equipment and its installation meets Canadian standards. This piece of equipment is ideal for fire safety in public locations such as schools, hospitals, mills, etc.

STI™ product code: STI-1230/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 7.125 in x Height 10 in x Depth 5.5 in
(Length 18.1 cm x Height 25.4 cm x Depth 14 cm) 

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

Polycarbonate thickness: 0.095 in (2.4 mm) 

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

Covers with English labeling are also available when permitted by local regulations (see item ESCTI1230).

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: Ruggedness and Reliability

Ideal for industrial environments or building retrofits where wiring is exposed:

• Surface Mounting Spacer Included: The deep spacer frame ensures the cover fully encloses the pull station without interfering with the lever mechanism, even on protruding backboxes.

• Superior Impact Resistance: Molded from high-strength polycarbonate (the same material used in police riot shields), it acts as a heavy-duty shield against forklifts, moving equipment, or sports balls.

• Accidental Alarm Prevention: By requiring the user to lift the cover before accessing the lever, it virtually eliminates accidental triggers caused by passersby or equipment movement.

• Linguistic Compliance: Features clear instructions in French (compliant with Quebec safety regulations): “En cas de feu, soulever le couvercle et tirer la station.”

• Maintenance-Free: With no electronic components and no batteries to change, it offers a long-term "fit and forget" safety solution.

Technical Specifications

• Mounting Type: Surface mount (protruding).

• Material: UV-stabilized clear polycarbonate (resistant to yellowing and cracking).

• Local Alarm: None (Silent model).

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

• Components: Protective cover + deep conduit spacer.

• Certifications: UL/cUL Listed.

Application Guide: Recommended Zones

This protector is highly recommended for:

1. Warehouses & Factories: Anywhere mobile equipment (forklifts) operates near walls.

2. Parking Garages: To shield stations from vehicle impacts and debris.

3. Gymnasiums & Arenas: To protect against high-velocity ball impacts where a local siren is not desired.

4. Renovated Buildings: Where fire alarm stations are commonly installed on surface backboxes.

FAQ: Frequently Asked Questions

Can this be installed on a flush-mounted (recessed) station?

Yes, it can be installed, but it will protrude further from the wall due to the spacer frame. For a cleaner look on recessed stations, the "Flush Mount" model (without the spacer) is preferred.

Will the polycarbonate break under heavy impact?

The polycarbonate used is designed to absorb significant energy. While it may scratch under extreme abuse, it is engineered to remain intact and protect the device inside without shattering.

Occupational Health and Safety (OHS) Expert Advice

• Clearance Check: When installing on surface-mounted boxes, ensure the cover can swing open to at least a 90-degree angle without hitting overhead pipes or electrical conduits.

• Cleaning: Avoid abrasive cleaners or solvents. A soft cloth with lukewarm water and mild soap will preserve the cover’s transparency for many years.

• Security Choice: If your facility faces recurring malicious false alarms (intentional vandalism), consider upgrading to the STI-1130 model, which includes a deterrent local siren.

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. 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.

Need additional safety equipment? See the following items: