Imager head adjustable mirror mount for borescope

A remote inspection device imager assembly includes an imager body having a male threaded portion. An accessory assembly includes: a tubular body portion having first internal female threads engaged with the male threaded portion such that tubular body portion rotation axially translates the tubular body portion with respect to the imager body; and a mirror obliquely angled with respect to a longitudinal axis of both the imager assembly. A threaded coupler positioned between the imager body and tubular body portion has second internal female threads engaged with the male threaded portion. The threaded coupler is selectively axially translated by rotation to a first contact position with the imager body or a second contact position with the tubular body portion. The second contact position binds the first and second internal female threads with the male threaded portion to prevent tubular body portion axial rotation and fix a mirror orientation.