STI-6518

Active
UL LISTED (US & CANADA)

STI-6518 Bopper Stopper — Clear Protective Push-Button Cover (spring hinge)

STI (Safety Technology International) Stopper II Series Introduced circa 1990

STI Bopper Stopper — clear polycarbonate spring-hinged protective cover for push buttons/keypads/outlets. Passive cover, no horn.

Common Applications

The red protective cover over emergency buttons and fire alarm pull stations in every school, hospital, and commercial building. Lift the cover to access the button underneath — the built-in horn sounds when the cover is raised, deterring false alarms. Polycarbonate is virtually unbreakable. The most recognizable safety product in commercial buildings.

Specifications

Certifications
UL Listed (US & Canada)
Color
Clear
Dimensions
~5in H x 3-3/16in W x 1-3/4in D (mounting plate included)
Material
Polycarbonate cover/hinge; stainless-steel hinge springs
Mounting Type
Surface mount over existing device
Operating temp
-40F to 250F (-40C to 121C); flammability 94V-2
Type
Protective cover (spring-hinged, passive)

Installation Quick Reference

Panel cutout: 22mm. Insert from the front of the panel, secure with mounting nut from behind (tighten to 2-3 Nm).

Contact block: Snap or screw the contact block onto the rear of the button body. Ensure the contact block orientation matches the wiring diagram — NO terminals are usually marked.

Wiring: Use 0.5-2.5mm² stranded wire with ferrules. Tighten screw terminals to 0.8 Nm. Test the button function before energizing the circuit.

Dimensions

Troubleshooting

Button doesn't respond when pressed

Check the contact block first — it's the most common failure point. Test continuity across the NO or NC terminals with a multimeter. If no click is felt, the return spring in the head may be broken.

Works intermittently

Contact block contacts are pitted or burned. Replace the contact block — don't try to file the contacts. Check if the rated cycle count has been exceeded.

Button feels mushy or doesn't click

The spring return mechanism in the button head is worn. Replace the head. The contact block can usually be reused if it tests OK.

Where to Buy

Price range

$55.28 — $98.38

across 2 distributors

Quick Specs

Certifications
UL Listed (US & Canada)
Color
Clear
Dimensions
~5in H x 3-3/16in W x 1-3/4in D (mounting plate included)
Material
Polycarbonate cover/hinge; stainless-steel hinge springs
Mounting Type
Surface mount over existing device

What People Are Saying

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