the "katanpää"-class vessels will be equipped with an extensive array of equipment to search for, locate and destroy naval mines, ranging from two autonomous underwater vehicles (auv) and two remotely operated vehicles (rov) to hull-mounted sensors. the larger auv, hugin (high precision untethered geosurvey and inspection system), which is manufactured by kongsberg maritime, is over four meters long and weighs over . it is equipped with a multibeam echosounder (mbes), a smaller version of the one mounted on the hull of the vessel. this instrument is used to collect topographic information of the seabed and a synthetic aperture side-scanning sonar can be used to detect and classify targets. the smaller auv, remus 100 (remote environmental monitoring unit), weighs only and can be used to collect information of the sea floor with its side-scanning sonar at depths of up to 100 metres. two rovs, a double eagle by saab underwater systems of sweden and seafox i by atlas elektronik of germany, can be used to identify and destroy naval mines. the hull-mounted sensors include a kongsberg em-710 rd multibeam echosounder and a topas (topographic parametric sonar) sediment echosounder with jets that can penetrate the uppermost strata of the seabed. in addition the vessels will be equipped with american-made klein associates klein 5500 towed side-scanning sonars. underwater positioning is provided with kongsberg hipap 500 (high precision acoustic positioning) system. the vessels follow a toolbox principle in which a suitable combination of sensors and equipment is selected individually for each mission according to the task and environmental conditions.