Truck Capswindow Seals
How to Choose the Right Rubber Boot Seal
You can purchase rubber boot material for your special project. This seal is extruded from resilient EPDM synthetic rubber substance and integrates a pliable spring steel clip for fastening to any flange. This material is sold by the foot. To determine how much you require measure the distance around your cab opening. You get three options of rubber to use for waterproofing your cabs together.
Tips for Getting the Right Fit
To find how much you need measure the space around your cab opening. It is vital that both openings are accurately the matching size. Make sure to measure the opening before ordering. Every installation is different.
Universal Fit: Compatible Rubber Seals for Trucks and Rigs
This rubber boot seal is frequently used in cab pass-through conversions. It's works with most standard trucks. Whether you're retrofitting a camper shell or building a DIY rig, this seal offers universal fitment and dependable performance for your cab connection project.
Truck Capswindow Seals Features and Benefits
| Feature | Benefit | Use Case |
|---|---|---|
| U-Channel Orientation Consistency | Both U-shaped edges face the same way for easier installation | Helps avoid confusion during install, especially for beginners |
| Affordable, High-Value Solution | Great quality at a competitive price point | Cost-effective choice for budget-conscious builders |
| Proven on Sleeper Cab Trucks | Successfully used between cab and sleeper on heavy-duty trucks | Ideal for semi trucks |
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.
$8.25 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
- Will the truck capswindow seals work with thin metal or wood frames?
Yes, but there must be a flange no thicker than 3/16". For wood or thick materials, add a metal strip (like aluminum flat bar) around the opening for the truck capswindow seals to grip.
- Can I keep my sliding windows and still use a truck capswindow seals?
Unfortunately, no. The slider windows must be removed because the truck capswindow seals requires a clean flange or wall to attach. Sliders block access to this area.
- Is it suitable for sealing between an airbag mounted truck cab and the body hard mounted to chassis rails on a truck?
As long as there is some sort of flange or wall to install the boot it should work. The thickness of the flange should not exceed 3/16" (4.7625mm) The accordion design allows for independent movement or flex between the cab bodies.
