Truck Cap Donut
How to Choose the Right Rubber Boot Seal
You can buy rubber boot material for your special project. This seal is extruded from long-lasting EPDM synthetic rubber substance and incorporates a bendable spring steel clip for fastening to any flange. This material is available by the foot. To find how much you require measure the length encircling your cab opening. You have several choices of rubber to employ for sealing your cabs together.
Tips for Getting the Right Fit
To specify how much you require measure the length around your cab opening. It is imperative that both openings are accurately the matching size. Make sure to measure the opening before ordering. Every installation is unique.
Don't Settle for Less: Upgrade to a Seal Built for the Road
Choosing the right seal is important for your vehicle project. This rubber boot delivers due to its superior construction and customer-approved reliability. We take pride on providing products that surpass your needs for long-term satisfaction. Don't settle for low-end seals, upgrade to one that's built to last.
Truck Cap Donut Features and Benefits
| Feature | Benefit | Use Case |
|---|---|---|
| Forgiving Fit | Can accommodate minor mismatches in height and width | Useful for older vehicles or hand-cut openings |
| Aesthetic Finish | Clean, professional appearance enhances your build’s look | Great for show rigs, restorations, or resale appeal |
| Prevents Heat and Sound Transfer | Improves cab comfort by blocking wind and road noise | Useful for sleepers and audio builds |
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
- Can I keep my sliding windows and still use a truck cap donut?
Unfortunately, no. The slider windows must be removed because the truck cap donut requires a clean flange or wall to attach. Sliders block access to this area.
- Will the truck cap donut work on a walk-through truck conversion?
Yes! This is a perfect use case. The truck cap donut allows you to join the truck cab and camper shell or utility box with a weather-sealed, flexible connection.
- Will one of these work on both sliding windows on truck & cap? I don't want to remove either sliding window.
In order for the boot to attach to the vehicle there must be some sort of thin wall or flange. Keeping the slider window will cover any flange or thin wall. In short you will not be able to use any or the boots if you keep the sliding windows in place as there will be no mechanical method to install the boot.
