Hello Sir. We're sorry to hear that your ESS Elastic Retention Strap is not compatible with the ESS Crosshair One. We copied the product description from the ESS website which says it is compatible with Crosshair. Link: https://www.esseyepro.com/Elastic-Retention-Straps_273_detail.html .

Anyway, we accept returns and replacements within ten (10) calendar days from the day you received the package. Kindly ensure that the item must be returned to us in its original unused condition. You may change it to another item or we can refund your payment via store credit which you can use on your next purchase or thru bank deposit. Just advise us. Thank you. :)