Theodolite that uses a digital sensor to measure the horizontal and vertical angles and display them on the instrument. Can often be combined with a EDM to measure distances. The electronics than allow the reduction of slant range to a horizontal / vertical distance making them electronic tachymeters. The horizontal and vertical angles are always measured at the same time although some instruments can not display both of them at the same time. Most instruments in my collection are by Wild Heerbrugg.