The STN Elite XL is a compact and portable voice and fax encryptor, designed specifically for the needs of government users. It operates 'in-line' between the phone or fax and the telephone wall socket, providing complete end-to-end secure communications, and is fully compatible with other products of the Elite series, including the Elite XT Secure Telephone and Elite XC Cellphone Encryptor. Each Elite XL can be configured to meet specific user requirements, such as default settings for voice or fax communications and adjustment of send and receive signal amplitude levels.

Full control of the system is via a password-protected menu. The Elite XL also features built-in self-test software and provides visual confirmation of changes between secure and clear operation. Closed user groups can be defined by programming a unique Corporate Code that can be used with or without PIN modification for enhanced security. In addition, a Global Code permits secure Communication between different organisations. A PC Based program is available to government users to allow complete customization of the algorithm and encryption process. The algorithm in the Elite XL uses an analog encryption environment with 128-bit key length, giving a number of advantage such as :