It is intended to guide directional and horizontal drilling of oil-gas boreholes without any limitations on hole orientation and length.

With a special configuration of a downhole device the system can be used in drilling of second holes from the cased boreholes of old resources.

Distinctive features:
- use of a bottom-hole gyroscopic inclinometer with the compassing effect without systematic errors at each start;
- compensation of influence of magnetic masses of a bottom-hole motor and a drillstring on a ferroprobe inclinometer;
- use of non-contact channel for data exchange between modules of the downhole device;
- manifold possibilities for downhole device control from the surface.
Diameter of the downhole device is 44.5 mm