Modular accessories for head-mountable device

An auxiliary component removably attachable with a head-mounted device, the head-mounted device including a first side arm with and an extension arm extending at least partially therealong and configured to present information to a wearer via a display coupled to the extension arm, a second side arm opposite the first side arm, and an external connection feature connected with internal circuitry of the extension arm, the auxiliary component comprising:

• a first attachment member configured to removably attach the auxiliary component with a portion of the second side arm of the head-mounted device, the first attachment member having a proximal end and a distal end;
• a first housing containing a first electronic component therein, the first housing having a proximal end adjacent to the distal end of the first attachment member and a distal end;
• and
• a wiring component in communication with the first electronic component, the wiring component having a proximal end adjacent to the distal end of the first housing and a distal end configured to attach with the external connection feature of the head-mounted device.