A-20K Dual frequency transducer, 200 and 400 kHz. Smallest in the world with such specifications! Allows replacement without docking a vessel (with G-20K), dry sluice valve is also available. - A-25K Single frequency transducer, 100 kHz. Intended for navigation echo sounder NEL-M3B. - A-39K Dual frequency transducer, 50 and 200 kHz. Allows to measure depths up to 1000 m. - Hermetic encapsulation device G-20K Intended for replacement of transducer without docking a vessel. - Remover Intended for transducer replacement in sluice valves on an abovewater position of vessel without docking.