Retrofit Polycarbonate Security Glazing System


DefenseLite is a transparent safety glass system that attaches to existing windows and doors to form a protective layer designed to “block the bad guys”. DefenseLite overglaze is an affordable solution to reduce criminal attacks with patented technology that is 250 times stronger than glass and virtually invisible once installed.

DefenseLite is an engineered forced-entry solution that combines the fundamentals of scientific materials with an efficient retrofit installation, using a high gloss polycarbonate UV protective film, breathable aluminum extrudate, multilayer film, strong structural adhesives, VHB tape, and security tipped anchors.


Patented vented extrusion mounts to the existing glazing frame creating standoff for the polycarbonate shield from primary glass

“Unbreachable” UV capped, clear polycarbonate shield is secured to the vented extrusion with security “flex” screws and elastomeric VHB tapes

“Super bond” anchoring method secures the engineered system to the existing glazing providing for unmatched flex, tensile and tear strength upon attack

Customized powder-coating creates full aesthetic integration with existing glazing upon retrofit installation


DefenseLite polycarbonate security panels are mounted to your existing glazing frames using a custom vented aluminum extrusion that creates a stand-off from your primary window and door glass. During an attack, a modified safety glazing system bends, absorbs, and deflects to prevent intruders from entering. In most cases, the main window will not be broken after installing our overglaze safety panel, and criminals will leave the area. DefenseLite’s patented pending ventilation system dynamically moves air through the glazing frame to prevent condensation, eliminating expensive and dirty humidity issues.


As smash-and-grab crimes, theft, forced entry, and political sabotage escalate, Defense Lite security glazing keeps things that’s important to you:

Stop unwanted entry through glass

Protect your inventory from theft

Protect your store (and your brand) from glass-related damage and unwanted attention

Enhance security where grills and gates are not the answer

DefenseLite also is an effective insulator

Reduces sound transfer by 50 percent

Protects against infrared and UV rays

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DefenseLite Polycarbonate Security Glazing Demo

DefenseLite FAQs: Comprehensive Guide to Overglaze Security Solutions

General Information

What is DefenseLite?

DefenseLite is the ‘flexible’ and ‘vented’ overglaze security solution. A patented technology, DefenseLite is a ‘clear security shield’ that installs over existing window and door glazing creating a layer of protection designed to ‘keep the bad guys out’. DefenseLite shields are 250 times stronger than glass, nearly invisible once installed and a long-term forced-entry solution that works. Utilizing proprietary high-optic UV coated polycarbonate shields, patented vented extrusions, multi-layer thin films and tough structural adhesives and flexible security tipped anchors, DefenseLite is an engineered system that combines the best of materials science with an easy to retrofit installed solution.

What makes DefenseLite a superior ‘overglaze’ security solution for windows and door glass?

Better quality components and superior mechanical and thermal engineering separates DefenseLite from less expensive competitor systems. DefenseLite is a patented ‘flexible’ and ‘vented’ overglaze system that provides for unmatched resilience under robust attack. Our patent pending venting system protects customers from longer-term condensation and moisture related issues inherent in hermetically sealed, non-vented, field installed overglaze systems.

Technical Features

Why is a ‘vented’ overglaze system critical for long-term system integrity?

In field conditions, it is not advisable to hermetically seal the air space between over-glazing and the prime window. Why? It won’t work.The only time ‘sealed airspaces’ work is in factory sealed, dehydrated insulating glass units. These ‘sealed IG units’ are built in controlled, factory conditions. To address this properly, DefenseLite overglaze systems utilize our patent pending ‘engineered ventilation’ behind the field installed overglaze.

This passive design is ’tuned’ for the local climate conditions and usage. The DefenseLite ‘engineered venting’ system basically dries out the air behind the overglaze on an ongoing, dynamic basis leading to a low likelihood of longer-term condensation or moisture issues. Less expensive, non-vented overglaze systems will experience moisture and condensation issues once the desiccant entombed in the framing system becomes saturated leading to an expensive fix for the building owner down the road.

What is ‘Engineered Ventilation’ and why is this critical to system integrity?

Each DefenseLite system is engineered for the local climate and usage so that the airspace behind the overglaze is ventilated to the adjacent space that is predicted to be drier at the most critical times of the year. Then, a precisely calibrated array of passive vents, based upon the premise of Boyle’s Law, are deployed to make the magic happen, keeping your overglaze system condensation free for the long-term.

Will ‘desiccant only’ systems work to mitigate moisture and condensation over the long term?

No. Field installed overglaze systems create a new airspace that requires airflow to mitigate condensation buildup in the newly created void. Without proper airflow, moisture will build up and create problems for the customer in many climate zones over time. ‘Desiccant only’ moisture control systems will eventually fail to control the condensation once the desiccant is exhausted and overwhelmed leading to foggy, unattractive windows and doors that will be very expensive to fix down the road.

Why is a ‘flexible’ system important for maximum protection from forced entry?

Each component in a DefenseLite system is designed to ‘flex’ under significant force from robust attack. As the DefenseLite system ‘flexes’ while absorbing impact, energy is dissipated evenly throughout the overglaze providing for increased performance over competitor’s less expensive, rigid and fixed designs. DefenseLite overglazing is like a Zen Master. It doesn’t attempt to ward off intruders like a brick wall. Instead, it flexes and absorbs the impact, dissipating the forces harmlessly out to the edges of the panel. Without breaking, tearing or detachment. Bad guys get frustrated with our flexible resistance and soon move on to a more vulnerable victim.

How does DefenseLite control the “pillowing” effect prevalent in other plastic glazing solutions?

‘Pillowing’, or ‘bowing’ prevalent in some plastic glazing creates unsightly distortion and ‘fun house’ mirror effects. Pillowing occurs when thermal (solar heat) buildup creates a condition where the plastic glazing expands, or ‘pillows out’ due to increased barometric air pressure and thermal expansion. The patent pending “Moore” venting system engineered into DefenseLite allows for dynamic airflow from the newly created airspace to an open space alleviating the increased air pressure caused by solar heat gain. The DefenseLite overglaze is flexible and super strong. Like all polycarbonate, the sheet tends to grow when it gets warmer. When plastic over-glaze “pillows” within a fixed rigid frame, it is because it is trying to grow – but it can’t – so it bulges out instead. DefenseLite’s engineered ventilation keeps the panel ‘cooler’ so it grows less, eliminates the pressure and allows the panel to float at all edges. Result: No unsightly bulge!

Material and Durability

How are DefenseLite polycarbonates unique from commercial polycarbonate sheets?

DefenseLite’s polycarbonate sheets are made to a proprietary specification that ensures optical clarity, low distortion, and UV protection, manufactured by Plaskolite.

Will the DefenseLite polycarbonate yellow from sun exposure?

No. The polycarbonate sheets are UV capped and warranted against yellowing for at least 7 years. Additional UV protection is often provided by a thin film laminate.

What are the largest openings that can be covered with DefenseLite without a seam?

DefenseLite offers single sheets as large as 156” x 96”, suitable for oversized windows.

Additional Benefits

What are the benefits of DefenseLite other than security?

DefenseLite reduces street noise by up to 40% and improves energy efficiency by over 50%. It protects primary glass from breaking and incorporates a sacrificial film for graffiti protection.

Installation,Cost and Warranty

How is DefenseLite Installed?

DefenseLite is installed by certified dealers/ installers over existing glazing. It is mounted to the exterior or interior of window and door frames, creating an airspace that mitigates pillowing and condensation, and is nearly invisible upon completion.

How much does DefenseLite cost?

DefenseLite systems cost between $30 to $75 per square foot, depending on design and project scope. BulletShield installations range from $175 to $450 per square foot.

What is the warranty for DefenseLite?

DefenseLite warranties range from a minimum of 2 years up to 15 years depending on the system installed. Custom warranties and service agreements are available.

Comparisons and Programs

How does DefenseLite compare to other solutions?

DefenseLite offers clear, unobtrusive protection and performs better than security films, roll-down grills, gates, and laminated glass. It is more durable and easier to replace if damaged.

Are there special programs for NSSF members?

Yes, DefenseLite offers discounted installed systems for NSSF members to help prevent firearm theft.

Are there special programs for RILA, NRF, LPRC, and CLEAR members?

Yes, DefenseLite offers special pricing, warranty programs, and service agreements for these groups to combat smash and grab crimes.

Security Glass Information

What is security glass?

Security glass refers to reinforced glazing products that delay or prevent intrusion or ballistic attack. This includes tempered, laminated glass, and polycarbonate security panels, designed to prevent forced entry and hold up under severe conditions.

What is security glass made of?

Security glass includes laminated glass, which bonds glass sheets with a plastic interlayer, and polycarbonate security shields like DefenseLite, which are significantly stronger and more impact-resistant.

How much does security glass cost?

Costs vary widely. Laminated glass replacement is expensive, whereas retrofit solutions like DefenseLite are more budget-friendly, costing $45 to $90 per square foot.

How does security glass work?

DefenseLite’s polycarbonate panels flex to absorb impact, dissipating forces without breaking, and preventing entry.

What is the strongest glass for windows?

The strongest “glass” is actually polycarbonate, as used in DefenseLite shields, which are 250 times stronger than glass.

What is the most unbreakable glass?

DefenseLite polycarbonate shields are the most unbreakable, offering clear visibility and additional benefits like UV protection, noise reduction, and temperature stability.