... power supply, adapting voltage instability on board.Technology Parameters GPS/beacon signal: 12 channels GPS+SBAS, dual-channel search signal automatically ... : 283.5 KHz ~ 325 KHz Operation distance (basing on beacon signal): marine 500 km, land 200 km Positioning accuracy: 0 ... shock resistanceApplicationMarine surveying, dredging, engineering positioning, marine & island investigation Marine Beacon