Keep model generations together
Use the exact enclosure and cassette identities when comparing a legacy installation with the current RGB Pro Box listing.
Dimplex
Dimplex Optimyst RGB Pro Box Rear Glass Pane
From $397.99
Dimplex ·
Dimplex Optimyst Pro Box 40-Inch Rear Glass Pane — GBF1000-GLASS
An optional 40-inch rear glass pane for the documented Optimyst Pro Box application, opening the flame presentation to a second viewing side.
$397.99
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Application40-inch Pro Box
RoleRear viewing pane
Width40.55 in
Height15.28 in
A second view of the same fire.
GBF1000-GLASS turns the compatible Pro Box’s opaque rear face into a transparent viewing surface. A single pane with black-edged vertical sides gives the water-vapor flame presentation a view from both adjoining spaces.
The manufacturer’s current accessory listing identifies this as the 40-inch rear-pane option. Choose the exact code for the enclosure and installation generation; similar Pro Box names do not establish interchangeable cassette or enclosure combinations.
Plan the rear viewing side as part of the complete enclosure installation. The glass does not replace required ventilation, structural support or service access, and its measurements are separate from the framed opening.
Plan both sides of your hearth.
Catalog dimensions below describe the pane itself. Use the exact enclosure guide for framing, support and installation requirements.
| Rear-pane width | 40.55 in |
|---|---|
| Rear-pane height | 15.28 in |
| Named size application | 40-inch Pro Box |
| Accessory role | Optional two-sided rear pane |
Allow the required access
Plan rear-panel access, surrounding finish and appliance ventilation before the installation is closed in.
The right pieces, clearly accounted for.
| In the box | Contents & quantities |
|---|---|
| Selected accessory | GBF1000-GLASS rear glass pane |
| Panel description | Single transparent pane with black vertical edges |
| System components | Firebox, cassettes, heater and decorative media sold separately from this accessory |
Know exactly what you’re bringing home.
Product specifications
- Manufacturer model
- GBF1000-GLASS
- UPC
- 781052116979
Rear-pane dimensions & role
- Rear-pane width
- 40.55 in
- Rear-pane height
- 15.28 in
- Named size application
- 40-inch Pro Box
- Accessory role
- Optional two-sided rear pane
Let’s get your project right.
What does the rear glass change about the finished fireplace?
GBF1000-GLASS replaces the compatible Pro Box’s opaque rear backer with a transparent pane, creating a view through the flame presentation from the other side. It is a finishing accessory for a documented two-sided arrangement, not another firebox or a second flame system.
Which nominal Pro Box size is this pane listed for?
The August 2026 manufacturer price list identifies GBF1000-GLASS as the 40-inch RGB Pro Box rear glass pane. Match that exact accessory code and the complete enclosure model. Older catalog records also name earlier Pro Box applications; that does not mean every old enclosure and new cassette combination is interchangeable.
Is this the front glass supplied with the RGB Pro Box?
No. The current RGB Pro Box package lists front glass among its supplied components. This is a separate rear pane for the two-sided configuration. Check the appliance package and the intended viewing arrangement so the included front glass is not mistaken for a missing accessory.
Does a second viewing side mean heat comes out in both directions?
The rear-pane listing establishes a second viewing side, not a second heat outlet or a different heater rating. Use the exact Pro Box installation guide to plan heat discharge and ventilation. Do not infer the airflow arrangement from the transparent glass or the two-sided photograph.
Can I use these dimensions as the framed opening?
The catalog gives this accessory a width of 40.55 inches and a height of 15.28 inches. Those are rear-pane dimensions, not enclosure or rough-opening dimensions. Build the opening and support to the exact appliance instructions, then use the accessory identity to check the selected rear-glass arrangement.
Should I order both rear panes for one installation?
The 40-inch and 60-inch selections are alternative pane sizes for different documented applications. They are not pieces to stack or combine into a larger rear panel. Keep the complete enclosure model with the selected accessory code throughout planning and ordering.
Does this kit supply water-vapor cassettes or decorative logs?
This separate accessory is the rear glass pane. It does not add a cassette, heater, water connection or decorative log package to an enclosure. Review the exact appliance’s included-equipment table and any separate required components instead of treating rear glass as a complete fireplace system.
Can the rear pane be added after the wall is finished?
Plan the two-sided arrangement before closing the surrounding construction. The compatible Pro Box guide governs access to the back panel, framing and finishing sequence. Do not assume the panel can be exchanged through any finished opening; leave the service and installation access required by that exact system.
Does replacing the backer remove ventilation or service requirements?
No. The glass is part of a finished viewing arrangement, not an exemption from the appliance’s fresh-air, support, electrical or service-access requirements. Keep those provisions in the installation design, and follow the exact enclosure guidance rather than sealing every visible gap around the glass.
What information helps verify a legacy Pro Box installation?
Have GBF1000-GLASS, the full enclosure model, the cassette model or models and the installed front/back arrangement available. An older family name alone is not enough to confirm a modern system combination. The linked resources identify their appliance scope; a separate rear pane does not automatically inherit an appliance warranty period.
CONFIDENCE BEYOND THE FIRST FIRE
The right fit. The right support.
Keep the rear-glass code, enclosure and cassette model numbers, and purchase record together for support. The linked documents explain their compatible appliance systems; the separate glass pane does not automatically inherit the appliance’s warranty period.
Manuals & documents
Optimyst Pro Box system overview GBF1000 Pro Box system architectural specificationsA real person. Useful advice.
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We can help check the rear-pane code against the complete enclosure model and planned viewing arrangement.
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The Dimplex story
A different way to bring fire home.
Dimplex’s electric-flame story includes the original Optiflame® effect, introduced in 1988. Its continued development of electric fire experiences includes Optimyst® water-vapor technology, which combines cold water vapor and light to create a moving flame illusion.
Part of the Glen Dimplex Group, the brand offers electric fireplace designs for residential, commercial and hospitality spaces. At Hearth Outpost, explore the different forms, flame technologies and installation approaches to find the one that belongs in your project.
Visit the Dimplex Shop by Hearth Outpost