Acorn Naturalists gift certificates are ideal gifts for teachers, environmental educatiors, naturalists, children, and parents! They can be used for internet, phone, or mail purchases by your recipient. If you do not find a dollar amount you are looking for online, call us and we will issue a custom amount for you. Acorn Naturalists gift certificates have no expiration date, sales tax, or shipping fees. During checkout, use the "Comments" section to let us know if you'd like your certificates mailed via Priority Mail or scanned and emailed. Include delivery addresses/email addresses and any notations desired in the "Comments" as well.