Raymarine RV-320 Plastic Thru-Hull Transducer Pack w/20 Deadrise Compensation [T70321]RV 320 Plastic Thru Hull Transducer Pack with 20 Deadrise Compensation Designed for inboard or outboard boats, the RV 320 Plastic Through Hull Transducer System lets you easily identify structures and locate fish with the life like clarity of RealVision 3D sonar. The RV 320 system is a 4 channel, Wide Spectrum CHIRP transducer system with DownVision, SideVision, high frequency CHIRP fish targeting and RealVision 3D sonar inside. The transducer system