Theft Prevention: Locks Cannon Optimum or Magnum downrigger (sold separately) securely to boat to prevent theft or unauthorized removal Pin-Tumbler Security: High-security pin-tumbler lock mechanism provides ultimate security that resists picking or forced entry Secure Boat Attachment: Prevents downrigger separation from mounting base during transport or rough water operation for added safety Optimum/Magnum Compatible: Works with all Cannon Optimum and Magnum models for protection of valuable electric downrigger investments Made in USA: American-manufactured quality ensures reliable locking mechanism and consistent fit across compatible models