The crew of the Enterprise use this mid-22nd century precursor to the tricorder on numerous occasions throughout the series, particularly on away missions, where it gets considerably more screen time than the phase pistol, communicator, or padd.
Custom designed and fabricated hero replica, created by extensive modification of a static resin kit, with spring-loaded popup activation of the brightly backlit display graphic.
By Buddahaid, from a kit by Thermalized Plastics.