The precise level was made in 1973. Its original technological solutions, and above all its precision, make it the leading precise level. The compensator, which is a double-sided silvered mirror on a pendulum and insensitive to heating caused by solar irradiation, enables measurement in two positions of the compensator; the position of the line of sight of the two positions is intended to define a quasi-absolute horizontal line. The swivelled eyepiece of the telescope allows the operator to measure laterally alongside the tripod without moving.

The precision of the level is 0.2 mm for 1 km double-run levelling, making it one of the most precise levels of all time and versions. Due to the positive response, Carl Zeiss continued to make improvements and developed a successor, the RENI002A, which represents the culmination of the development of optical levels.

The instrument was still used in the first decade of the millennium for teaching and also for professional work at the Faculty for the most accurate height measurements. The multiple measurements of the research levelling net for the determination of the subsidence of the Ljubljana Marshes have achieved superior measurement accuracy.

The instrument is in the same condition as it was when it was originally taken out of service.