SeaStar HA5418 Back Mount Kit for SeaStar Standard Helms Used to retrofit a new SeaStar standard helm in the old 4.5" diameter hole; Reduce the helm protrusion from the dash by the thickness of the dash; Retrofit new SeaStar standard helm into old cutouts for mechanical and hydraulic steering; STEERING MANUFACTURER HELM MODEL TYPE SYSTEM BACKPLATE KIT REQUIRED SeaStar SAFE-T MECHANICAL YES BIG-T MECHANICAL YES ROTARY MECHANICAL NO RACK & PINION MECHANICAL NO SYTEN HYDRAULIC YES MORSE ROTARY MECHANICAL NO RACK & PINION MECHANICAL NO