SB-10BLSwitches 2 Sonar units between 1 Transducer.Works with: LCX-110C, LCX-111C HD, LCX-112C, LCX-113C HD, LCX-17M, LCX-20C, LCX-25C, LCX-26C HD, LCX-27C, LCX-28C HD, LCX-37C, LCX-38C HD, LMS-480, X102C, X125, X135, X-510C