iON SYNC® DIY Earthing Shoe Kit
iON SYNC® DIY Earthing Shoe Kit
iON SYNC® DIY Earthing Shoe Kit
iON SYNC® DIY Earthing Shoe Kit
iON SYNC® DIY Earthing Shoe Kit
iON SYNC® DIY Earthing Shoe Kit
iON SYNC® DIY Earthing Shoe Kit
iON SYNC® DIY Earthing Shoe Kit

iON SYNC® DIY Earthing Shoe Kit

Earth Runners Sandals - Reconnecting Feet with Nature

Our innovative iON SYNC® Earthing Plugs have been developed over several years of dedicated research and development to create a highly durable and conductive solution for enthusiasts of earthing shoes.

When installed through the soles of shoes, iON SYNC® plugs offer users an unparalleled grounding experience that replicates the benefits of being barefoot.

These plugs are offered in three sizes, suitable for grounding shoes with thicknesses ranging from 4-15mm (3/16 - 5/8"). Please refer to this table to find the right size for your shoes, and find written -and- video instructions below.

Base Sole Thickness = Stack height - Lug height

Looking for Plugs only? Check out our iON SYNC® Refills!


Can the ion sync earthing plug be removed?

Yes, you can push the earthing plug through from the bottom by pressing hard with a medium sized philips screw driver (or something similar in diameter) on the flat barb surface after the pull tab has been removed.

Can the ion sync earthing plug be removed and reinstalled?

No, our earthing plugs can only be installed once. Once they are installed they can’t be reinstalled.

Are ion sync earthing plug watertight?

Yes, the compression fit rubber design up our earthing plugs mates with shoe outsole making a watertight seal when installed properly.

What makes these rubber ion sync earthing plugs conductive?

We worked with industry leading polymer experts to formulate a proprietary rubber formulation featuring a conductive filler to create a conductive network throughout the material that allows for electron transfer of low voltages--great for earthing.

How do I determine what size earthing plug to use for my shoes?

Determine the base thickness of your shoes (Base thickness = Stack height - Lug height) and then refer to our sizing chart. Most shoe manufacturers list the stack height (total sole thickness) on their product page. Then you just need to measure and subtract the lug height to account for the recession where you plan to install the earthing plug in the middle of the outsole. The height of lugs usually range from 2-5mm based on their level of all terrain grip.

If the base thickness of my sole is on the cusp of two different ion sync earthing plug sizes, should I order big or small?

We recommend going with the bigger size ion sync earthing plug if the base thickness of your sole is on the threshold of two sizes.

Do you feel the ion sync earthing plug underfoot?

If you properly install the earthing plug in the middle of the sole with the right size recessed into the outsole, you should feel it slightly when wearing your grounded shoes for the first time. After ~1 hour the sensation will normalize and you will forget it's there.

Do the ion sync earthing plugs work with socks?

Due to the weight of your body bearing down onto the head of the earthing plug head, combined with the common perspiration of our sole into socks, our testing has shown a negligible difference in the measurable voltage drop between when earthing wearing ion sync grounded shoes with and without socks.

How does the Ion Sync rubber earthing plug kit compare to the Shoe Syce copper earthing rivet kit?

Comfort:    Ion Sync rubber  [more comfortable than]  Shoe Sync copper

Installation difficulty:   Ion Sync rubber [easier to install than] Shoe Sync copper

Conductivity:   Ion Sync rubber [less conductive than] Shoe Sync copper



If it’s really hard to pull the earthing plug barb through the hole and seat it on the outsole?

Solution 1: Use something like a screwdriver or a pen to pre stretch the hole through the center of your shoe before rehoming and quickly installing the earthing plug.

Solution 2: Use the next size up earthing plug that is a bit longer.

Solution 3: Use the next size up hole punch to cut a slightly bigger hole. (This should be your last resort.)



Our collaboration with a renowned compounding company, known for its work with top technology firms such as Apple, Tesla, and SpaceX, has resulted in the development of a unique composite material. This material blends the robust properties of shoe outsole rubber with the required conductivity to meet the standards for therapeutic earthing (less than 10^3 Ohms resistance).


Your order will ship out via USPS within 3-7 business days of receiving it. All orders placed by Monday 7am Pacific will be shipped Thursday. Orders placed by Thursday at 7am Pacific will ship Monday. Any changes to your order must be requested within 48 hours of placing your order.

All sandals are made to order in our Sonoma County workshop. *Please note we cannot guarantee changes made to your order 24 hours after it has been placed*


  • First Class Mail cost $3-5 and takes 3-5 days for delivery from ship date.
  • Priority Mail (flat rate) cost ~$7 and takes 2-3 days for delivery from ship date.
  • Priority Mail Express (flat rate) cost $22.38 and takes 1-2 days for delivery from ship date.


  • We ship worldwide with Delivered Duty Paid (DDP) shipping options to help avoid unpredictable customs fees and shipping delays. Shipped via FedEx, DHL & postal mail, taxes & duties included. Learn more here.

    • DDP Priority: average 9-14 day transit time.
    • DDP Express: average 7-10 day transit time.
    • DDP ePacket (Canada only): average 9-12 day transit time.

*shipping costs are estimated based on the weight of 1-3 items

1% Donation

1% donation for Tarahumara Indians

Earth Runners are inspired by ancient huarache running sandals. We are grateful to the Tarahumara for originating this design and feel fortunate to have the ability to give back and honor the creators of the huarache running sandal.

We donate 1% of all sales to True Messages, a non-profit focused on honoring the running heritage that remains so important to the Rarámuri culture. True Messages listens to the input of the local National community to determine where to allocate resources which includes sponsoring races, trail projects, and initiatives to support the youth of the community.

Thank you for helping us support the Tarahumara!