T-H Marine T H Marine Atlas Heavy Duty Hydraulic Jack Plate 4in Setback. The ATLAS Hydraulic Jack Plate is the #1 selling jack plate on the world and the #1 choice by fishing professionals and boat manufacturers. With the new ATLAS Heavy Duty the product is available for applications on even larger outboards rated for engines up to 400 HP. Features of T-H Marine AHJ-4VHD-DP T H Marine Atlas Heavy Duty Hydraulic Jack Plate 4in Setback The ATLAS Hydraulic Jack Plate is the #1 selling jack plate on the world and the #1 choice by fishing professionals and boat manufacturers Heavy Duty version is rated for engines up to 400 HP The first and only plate that did not require regular grease lubrication Jack Plate Setback: 4" Package Contents: T-H Marine AHJ-4VHD-DP T H Marine Atlas Heavy Duty Hydraulic Jack Plate 4in Setback T-H Marine AHJ-4VHD-DP: T H Marine Atlas Heavy Duty Hydraulic Jack Plate 4in Setback