I copied this right off the Minn Kota Website. Looks like you need a MKR-US2-10. They are anywhere from $25-$30 online. Thanks, Ringo.

Required Accessory Adapter for Universal Sonar 2 Trolling Motors

Adapter # Sonar Brand Compatible Models

MKR-US2-10 Lowrance HDS-5, HDS-5X HDS-7, HDS-8, HDS-9, HDS-10, HDS-12, LCX-20C, LCX-17M, LCX-25C, LCX-26C,
LCX-27C, LCX-28C, LCX-37C, LCX-38C, LCX-110C, LCX-111C, LCX-112C, LCX-113C, LMS-330C, LMS-332C, LMS-334C, LMS-335C DF, LMS-337, LMS-339C, LMS-489, LMS-480 DF, LMS-520C, LMS-522C,
LMS-525C, LMS-527C, X-52, X-59 DF, X-100C, X-102C, X-105C DF, X-107C DF, X-125, X-126 DF, X-135, X-136 DF, X-510C, X-515C