The Eagle FishMark 320 Portable Fishfinder has all the outstanding features of the regular FishMark 320, plus:
A Streamlined Port-Power Pack Base for fishing-on-the-go anytime, anywhere. Sonar head unit folds down neatly on base. (8 D cell batteries required - not included) - Portable, high-performance 200 Khz Skimmer transducer with special suction-cup mounting bracket included (not intended for high-speed operation).
