further comprise an auxiliary body portion 2030 that connects with the brim b auxiliary body portion 2030 has an engagement structure that permits the auxiliary body portion 2030 to be selectively retained on a baseball cap brim b the auxiliary body portion 2030 may include a clip or similar member to fasten with or removably connect along the lateral edge of the brim b as shown the auxiliary body portion 2030 may further be connected to a wired lanyard interface 2035 by a port or by a wireless interface as mentioned the auxiliary body portion 2030 may provide increased functionality to the monocular display device 2000 by storing additional electronic components on a brim b of the baseball cap b while at the same time being very lightweight and compact in one embodiment the auxiliary body portion 2030 may further include a speaker 2040 or ear bud that connects with a jack or output port not shown of the monocular display device 2000 through the wired lanyard interface 2035 other previously described secondary components may be connected in the portion 2030 to expand the functionality of the device 2000 turning now to fig2 a and 21b there is shown two views of an embodiment of the display 2100 for the monocular display device 2000 as mentioned the display 2100 is configured to be lightweight and portable with a diagonal dimension less than one inch the display 2100 is also configured to have a.