How to Use Your EquuSound Sizing Keys

While this simple process can be accomplished by yourself, some horse owners may find it helpful to ask a friend for assistance. We recommend using a mounting block to help you select the best fit. Pulling the ear down towards you will deform the ear and result in selecting the wrong size earplug. Watch our video for a tutorial.

Step 1: Find 1 1/2" up From Base of Ear Opening

  • Insert the depth gauge into the width gauge and set to the 1/2" mark.
  • Set the tip of the depth gauge at the base of the ear opening.
  • Mark the ear at the 1 1/2 inch mark with chalk.

Step 2: Find the Best Fit

  • For the right ear (as pictured) start by placing the notch on the right side of the key against the ear. For the left ear start by placing the notch on the left side of the key against the ear.
  • Rotate the key clockwise until fully seated. For the left ear, rotate counter clockwise.
  • The best fitting key should contact the ear as pictured.
  • Run your finger along the inside of the ear to ensure there are no large gaps.
  • Holding the key at an angle will result in an inaccurate fit.
  • Holding the horse's ear while fitting may result in an inaccurate size.

Poor Fit Example: Key Is Too Small

This is an example of a poor fitting sizing key that is too small. See the large gap between the left side of the key and ear.

Poor Fit Example: Key Is Too Big

This is an example of a poor fitting sizing key that is too big. Although there are no gaps, you can see the bulge of the ear on the left side.

Step 3: Repeat Steps 1-2 For the Other Ear

  • Important: Even on the same horse both ears may not fit the same size key. This horse correctly measures as a QH-130 in the right ear, and a QH-150 in the left ear.
  • After fitting, complete the form below with your order number and size selections for each ear.
  • Feel free to keep your sizing keys and gauge or share them with friends and family.

Send Us Your Size Selections Below

Please fill out the form below completely. Place your order number and size selections in the comment section.