Brochures & User Guide. Clarus FX2 Brochure Industry's smallest and lightest and most affordable tactical in-ear hearing protection/enhancement system. Its in-ear microphone eliminates the need for an external boom mic. The FX2 also incorporates Silynx's Hear-thru and sound localization technology. With fixed cables to the headset and to the radio connector the FX2 is very simple to deploy. Power / hear-thru volume control button on front face of the control box. Supports single radio only. Clarus XPRFH & QH Brochure / Clarus XPRFH & QH User Guide. Clarus Brochure / Clarus User Guide.