Cap Window Seals
How to Choose the Right Rubber Boot Seal
You can buy rubber boot material for your special project. This seal is extruded from tough EPDM synthetic rubber substance and incorporates a bendable spring steel clip for fastening to any rim. This material is sold by the foot. To specify how much you need measure the distance around your cab opening. You get 3 choices of rubber to make use of for sealing your cabs together.
Quick and Easy Installation
Installing this rubber boot is simple and can be done with few tools. Just fit the seal firmly onto the frame of the window or pass through opening. This creates a secure connection between the two units. Regardless of whether you're hauling, this seal blocks debris and helps interior comfort during your journey.
Why EPDM Rubber Is the Best Choice for Long-Lasting Seals
The EPDM rubber seal is designed to resist harsh conditions such as cold. It's suitable for both commercial fleets. Compared to low-grade seals, this material offers more protection. It's a reliable option for anyone looking to enhance their truck cab connection with a dependable sealing solution.
Cap Window Seals Features and Benefits
| Feature | Benefit | Use Case |
|---|---|---|
| Flexible Bellows Design | Absorbs vibration and road movement without cracking | Great for off-road and long-haul driving |
| Prevents Heat and Sound Transfer | Improves cab comfort by blocking wind and road noise | Useful for sleepers and audio builds |
| Adapts to Slightly Uneven Openings | Flexible enough to seal even when openings aren’t perfectly aligned | Even though it is best that the opening match exactly there is some wiggle room to make minor adjustments for custom truck and canopy installations |
Order Form
To begin your order just enter the total amount of feet of boot material you need in the appropriate box next to the item you want to order below. Check your entries then click on the "Order Now " button.
Accordion Boot - Part Number 541
The accordion boot is designed for cabs where you take out the truck window. This product works best with fiberglass shells that are 1/8" to 3/16" thick. Please note that both openings must be exactly the same size for this boot to fit properly.
$8.95 per foot
In Stock
Order 541
- Enter the total amount of feet of boot material you need in the text box
- Check your entries, then click on the "Order Now" button.
Compression Boot - Part Number 540
Use this seal when you leave the rear slider window in the truck. This product works best with fiberglass shells that are 1/8" to 3/16" thick. You will also use this boot if the opening in the fiberglass shell is much larger than the opening in your truck.
$7.95 per foot
In Stock
Order 540
- Enter the total amount of feet of boot material you need in the text box
- Check your entries, then click on the "Order Now" button.
Extra Wide Accordion Boot - Part Number 543
The extra wide accordion boot is designed applications where you have a large gap between the space you want to seal. This product works best with fiberglass shells or sheet metal flange that are 1/8" to 3/16" thick. Both openings must be exactly the same size for this boot to fit properly.
$11.50 per foot
In Stock
Order 543
- Enter the total amount of feet of boot material you need in the text box
- Check your entries, then click on the "Order Now" button.
Accordion Boot - Ultra Wide 10" Part Number 544
The Ultra Wide 10 Inch accordion boot is designed for very wide gaps between cabs.. This product works best with fiberglass shells that are 1/8" to 3/16" thick. Please note that both openings must be exactly the same size for this boot to fit properly.
$13.90 per foot
In Stock
Order 544
- Enter the total amount of feet of boot material you need in the text box
- Check your entries, then click on the "Order Now" button.
Accordion Boot 15 - Part Number 546
The Accordion Boot 15 is designed applications where you have a large gap between the space you want to seal. This product works best with fiberglass shells or sheet metal flange that are 1/8" to 3/16" thick. Both openings must be exactly the same size for this boot to fit properly.
$16.50 per foot
In Stock
Order 546
- Enter the total amount of feet of boot material you need in the text box
- Check your entries, then click on the "Order Now" button.
Compression Bulb Seal - Part Number 545
Use this seal when you leave the rear slider window in the truck. This product works best with fiberglass shells that are 1/8" to 3/16" thick. You will also use this boot if the opening in the fiberglass shell is much larger than the opening in your truck.
$7.95 per foot
In Stock
Order 545
- Enter the total amount of feet of boot material you need in the text box
- Check your entries, then click on the "Order Now" button.
Frequently Asked Questions
- How weatherproof is the cap window seals?
The EPDM accordion boot creates an airtight, watertight seal when installed correctly. It's designed to keep rain, dust, and wind out — ideal for camper conversions and pass-throughs.
- Can I cut the cap window seals to fit around a third brake light?
No, cutting is not recommended. Instead, remove the brake light and cover the hole, or change how the boot is mounted if you need to preserve the light.
- What is an accordion boot?
An accordion boot is a flexible rubber connector that creates a weatherproof seal between two compartments, such as a truck cab and camper shell.