Byrna (BYRN) 8-K Changes in Registrant's Certifying Accountant

Exhibit 99.1

Schwartz  Levitsky Feldman llp

CHARTERED ACCOUNTANTS

LICENSED PUBLIC ACCOUNTANTS TORONTO • MONTREAL

November 30, 2017

Security Devices International Inc.

107 Audubon Road

Building 2, Suite 201

Wakefield, MA 01880

Attention:Mr. Dean Thrasher Chief Executive Officer and

                  Mr. Rakesh Malhotra, Chief Financial Officer 

Dear Sirs:

We hereby tender our resignation as auditors of Security Devices International Inc. with immediate effect. Our last involvement as auditors of the company and its subsidiary was for the fiscal year ended November 30, 2016.

You are responsible for filing an appropriate public notice disclosing our resignation. Please send us a copy of this filing as soon as it has been produced.

We appreciate the opportunity of serving as your independent registered public auditors. We would like to thank you and your staff for the cooperation we received.

Yours very truly,

SCHWARTZ LEVITSKY FELDMAN LLP

Chartered Accountants

Licensed Public Accountants

2300 Yonge Street, Suite 1500, Box 2434

Toronto, Ontario M4P 1E4

Tel: 416 785 5353

Fax: 416 785 5663