T-H Marine Pro Hi-Jacker Jack Plate The T-H Marine Pro Hi-Jacker is a 38 thick aluminum jack plate designed for V-6 Outboards with a maximum of 175 HP. Locking bars inside allow for the side locking bolts to be adjusted from the outside using a single wrench. Features all stainless hardware with brass nuts. Features High Strength Aluminum - 38 Thick One Piece Design - Top Adjust Locking Bars allow one wrench adjustment Maximum 175 hp Outboards 4 Vertical Adjustment 6 of Setback California Reside