Abstract: The invention provides an apparatus for mounting an electronic device therein for use in an underground boring machine. Such an apparatus includes an elongated housing having means at opposite ends of the housing for connecting the housing to other components of the boring machine and an elongated internal chamber configured to receive an electronic device such as a sonde therein and having an elongated access opening which extends along an exterior surface of the housing. A cover sized to close the access opening has edges that fit beneath one or more flanges of the housing. A retainer such as a roll pin is sized for insertion into openings in the cover and housing, which openings become aligned when the cover is positioned with the edges beneath the flange of the housing.