K1，未婚签证，提交I-129F申请时需要的说明信模版如下：
<petitioner’s name>
                                                                                    <petitioner’s address>
                                                                                    <petitioner’s phone>
 
                                                                                   
United States Department of Homeland Security
U.S. Citizenship and Immigration Services
<service center address>
 
                                                                                    <today’s date>
 
Re: I-129F petition
 
Dear Sir or Madam:
 
Enclosed please find the Form I-129F, Petition for K-1 Fiancé[e] for <beneficiary’s name>       and supporting documents as follows:
 

• Application fee  - $<455>
• Form I-129F
• Form I-129F Supplement: Part B, Question 18, explanation of meeting in person
• Evidence of my US citizenship
• Form G-325A and photograph of the petitioner
• Form G-325A and photograph of the beneficiary
• Form FC-029
• Proof of having met in person within last 2 years
• Letters of intent to marry, petitioner and beneficiary

 
Copies of documents submitted are exact photocopies of unaltered documents and I agree to submit original documents to an Immigration or Consular officer at a later date, if required.
 
 
Yours truly,
 
<petitioner’s signature>
 
<petitioner’s name>