The ZII is a versatile model that drives a wide range of high pitch from the development team to the wide area of the shallow and wide areas. It has a "hard contact building" with the rugged construction and design to make contact with the angler more clearly. "Instant Restoration of Posture from Obstacles and Bottom Contact, and "Tracability" that continuously contacts with any bottom. While we took two sizes up the body volume (required air volume) to provide the same contact performance, the ZII is an incredible compact size that allows for the overwhelming structer bottom. The ultimate search master with increased resolution to "visualization" for anglers to make the blind material contact.