The Duotone eHarness is the core of the Foil Assist system. Instead of loading all the weight onto the board, the eHarness carries the two compact 7Ah batteries securely around your waist. This keeps your board and foil feeling light and surfy, and puts the mass closer to your centre of gravity so the whole setup stays more responsive in turns and during take-off.
Built from buoyant, non-water-absorbing materials, the eHarness stays light in the water and doesn’t sag or drag behind you. The magnetic connection and quick-release hardware make clipping in and out fast and intuitive, while still giving you a positive, secure connection to the battery box and mast cable.
Key specs
Product: Duotone eHarness (harness only – no battery box or batteries included in this SKU)
Use: Waist-mounted support for Foil Assist battery box and cabling
Sizes:
- S–M: approx. 71–89 cm / 28″–35″ waist
- L–XXL: approx. 89–114 cm / 35″–45″ waist
Construction:
- Buoyant, non-water-absorbing foam and shell
- Broad, supportive belt section to spread load from the batteries
- Durable outer fabrics and robust hardware suitable for saltwater use
Features:
- Quick-release connection so you are never “locked in”
- Magnetic attachment to guide the plug and battery box into place
- Cable guides and routing points to keep the power cable tidy and close to the body
- Low-profile design to sit comfortably over a wetsuit or impact vest
Sizing & fit
Choosing the right size is important for comfort and control:
- S–M (71–89 cm / 28″–35″)
- Best for slimmer riders, teens and smaller adults
- Wraps snugly without excessive overlap of the belt
- L–XXL (89–114 cm / 35″–45″)
- For broader waists, thicker winter wetsuits or riders who prefer more overlap and padding
- The harness should sit low and snug on the hips/waist without being constrictive. A comfortable, secure fit stops the batteries shifting around during pump, carves or crashes, and helps the system feel like part of your body rather than something hanging off you.
Integration with the Foil Assist system
The eHarness is designed to work seamlessly with the rest of the Duotone Foil Assist platform:
- The battery box mounts directly to the harness, keeping the packs protected and close to your body.
- The power cable runs out from the box and along the supplied cable fasteners towards the mast, minimising drag and reducing the chance of tangles.
- In use, you simply clip the harness on, plug in via the magnetic connector and you are ready to go. When you’re done, the quick-release makes it easy to separate from the system on shore or in an emergency.
- For schools, centres and families, having multiple eHarnesses in different sizes with a shared set of batteries and masts makes it much easier to swap riders in and out without constantly re-rigging the board.
Who it’s for
The Duotone eHarness is for:
- Foil Assist owners who need a comfortable, purpose-built harness rather than improvising with generic belts or bags
- Schools and centres wanting multiple harness sizes so they can run one or two Foil Assist systems with a wide range of riders
- Families and groups who share Foil Assist gear and want a dedicated harness for each regular rider, sized correctly
- Anyone looking to replace a heavily used harness while re-using their existing battery box and electronics
Why it stands out
- Designed from the ground up for electric foil use, not adapted from a kite or windsurf harness
- Moves the weight off the board and onto your body, helping your foil still feel like a “real” foil setup
- Buoyant construction and clean cable routing reduce clutter and drag in the water
- Clear two-size range with published waist measurements in cm and inches, making it much easier to pick the right size online
Why buy from The SUP Company
At The SUP Company we use the Duotone Foil Assist system ourselves and in our test and demo environments. That means we understand how the eHarness behaves over long sessions, in cold-water wetsuits and with different body shapes. We can help you:
- Choose between S–M and L–XXL based on your actual waist size, suit thickness and riding style
- Decide how many harnesses you need if you are running shared or school setups
- Pair the eHarness with the right battery box, cables, Foil Assist mast and board so the whole system feels integrated, tidy and safe
