Humminbird - GM H7 Gimbal Mount for HELIX 7 Series - 740146-1. Replacement Mounting Bracket Kit includes attachment screws and knobs.. The GM H7 is a plastic gimbal mount for all HELIX 7 Series products. This includes the gimbal mount, knobs and mounting hardware.. Compatible Devices:. HELIX 7 Series - All models. WARNING: This product can expose you to chemicals including LEAD which is known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.