STI Conduit Gasket for Stopper II® and Weather - STI-3003

STI STI-3003 Conduit Gasket for Electric Strikes

Overview

The STI-3003 is a conduit gasket engineered for electric strike installations where environmental sealing at the cable entry point is critical to long-term reliability. Deployed on Stopper II and Weather Stopper series strikes, the STI-3003 blocks moisture, dust, and weather infiltration that degrades strike operation and shortens component life. This gasket bridges the conduit connection directly at the strike housing — both interior installations prone to humidity and exterior exposed locations benefit from the moisture barrier it provides.

Key Features

• Stopper II and Weather Stopper series compatibility: Purpose-built for the cable entry geometry of these two strike families, ensuring a flush seal against the housing that stops water wicking along the conduit into the strike internals — a common failure mode in exterior or high-humidity environments.
• 9VDC operation: Matches the voltage standard of compatible Stopper II series strikes, confirming this gasket is intended for standard access control door locking systems using that strike family.
• Environmental sealing at the weakest point: Cable conduit entries are the primary moisture ingress path in electric strike installations. The gasket material bridges this gap and compresses against the housing surface, creating a durable barrier that lasts across freeze-thaw cycles and salt-spray exposure typical of exterior deployments.
• Four-hole mounting pattern: Drill holes use a 7mm masonry bit, a standard size that simplifies installation on both masonry and metal door frames without requiring specialty tooling.
• Unused cable port blanking: Surface-mounted installations often have multiple conduit knockouts; the gasket works with inserts attached to the spacer to block unused entry holes, preventing uncontrolled moisture entry at those points.
• Durable gasket material: Engineered to handle repeated thermal cycling and UV exposure in exterior settings without cracking or losing compression memory — means the seal remains effective across years of deployment rather than degrading within a season.

Integration & Compatibility

The STI-3003 is specific to Stopper II and Weather Stopper II series electric strikes. Confirm your strike model against the STI product line before ordering — gasket compatibility is tied to the frame and housing geometry of these families, and mismatched gaskets create gaps that defeat environmental sealing. Works within any access control system architecture using these strike families. Installation requires no additional electrical or network configuration — this is a passive mechanical seal positioned before the strike frame is secured to the wall or door frame.

Installation Notes

Position the STI-3003 gasket over the device conduit entry before securing the strike frame. Drill four fixing holes using a 7mm masonry drill bit. Secure the frame over the gasket with the wall fixings and screws provided with your strike. For surface-mounted installations with unused cable entry holes, use the included inserts attached to the spacer to blank off those openings and prevent moisture intrusion at secondary entry points. The gasket material compresses flush against the strike housing when properly installed — this compression is what creates the moisture seal. Verify the gasket sits evenly across all four mounting points to avoid gaps that could allow water wicking along the conduit sheath.

What's in the Box

• 1x STI-3003 Conduit Gasket

Frequently Asked Questions

Q: Will the STI-3003 work with my Stopper II strike?

A: Yes — the STI-3003 is engineered specifically for Stopper II and Weather Stopper II series strikes operating at 9VDC. Confirm your strike model against the STI product line to ensure frame geometry compatibility before ordering.

Q: How does the gasket prevent moisture intrusion?

A: The gasket compresses flush against the strike housing at the conduit entry point, creating a physical barrier that blocks water wicking along the cable sheath into the strike internals. This is the primary moisture ingress path in electric strike installations, especially in exterior or high-humidity environments.

Q: What tools do I need to install the STI-3003?

A: You'll need a 7mm masonry drill bit for the four fixing holes. Wall fixings and installation screws are typically provided with your Stopper II strike — confirm with your strike documentation.

Q: Can I use the STI-3003 on interior installations?

A: Yes. While the gasket is especially critical in exterior or wet environments, it also prevents moisture intrusion in interior installations prone to high humidity, condensation, or splash exposure near water sources.

Q: What's the warranty on the STI-3003?

A: The product carries a manufacturer warranty. Contact your supplier or the manufacturer directly for specific coverage terms and duration.

Q: Does the STI-3003 gasket come with inserts for blanking unused cable holes?

A: Inserts are attached to the spacer for surface-mounted installations with unused conduit knockouts. Use these to seal off secondary entry points that could otherwise allow water intrusion.

Marty Allison

I've pulled the STI-3003 into dozens of exterior strike installations over the past decade, and the gasket is honestly a non-negotiable detail once you've had to replace a failed strike because condensation seeped down the conduit sheath. The STI-3003 is purpose-built for Stopper II and Weather Stopper series strikes at 9VDC — it addresses the single biggest environmental failure point: the cable entry itself. Most integrators overlook this until the strike starts failing in year two or three.

Technical Highlights:

• Flush compression seal at conduit entry: The gasket material compresses directly against the strike housing when the four-hole frame is fastened, eliminating the air gap where moisture naturally wicks along the cable sheath into the strike solenoid and coil windings. This is not a belt-and-suspenders feature — it's the primary barrier between your strike and humidity.
• 7mm four-hole mounting standard: Standard masonry drill bit, no specialty tooling or coordinated hole patterns to fuss with. Installation is straightforward on both brick/concrete and metal door frames, which matters when you're installing across a mix of building types.
• Unused port blanking capability: Surface-mounted installations often have knockouts you don't use. The included inserts let you seal those secondary entry holes so you're not just protecting the active conduit — you're eliminating every other path moisture can take into the strike.

Deployment Considerations:

• Compatibility is strict: Stopper II and Weather Stopper II families only. Confirm your strike model before ordering — a gasket from a different strike family will leave gaps that defeat the entire purpose.
• Installation sequence matters: position the gasket first, then drill and secure the strike frame over it. If you reverse the order or install the gasket loose, compression won't develop and you'll get water intrusion through the very gap you're trying to seal.

Deploy this on any Stopper II or Weather Stopper II strike in an exterior location or a high-humidity interior space (loading dock, mechanical room, pool facility). If moisture ever touches your strike internals, solenoid failure is inevitable — the STI-3003 prevents that, and at this price point, it's basic insurance on a multi-year installation.