This video compares the features and durability of the Model 19 and Model 3019 microR (µR) Survey Meters. The Model 19 has an internal 2.5 x 2.5 cm (1 x 1 in.) NaI detector and an analog meter. The Model 3019 has an internal 2.5 x 1.9 cm (1 x 0.75 in.) CsI detector and an auto-ranging, digital meter.