Mercury – Active Trim Kit (Without Trim Pad) | Single Engine | 3.4L V6, 4.6L V8, 150HP FourStroke & OptiMax 150–250HP | 8M0129439Mercury Active Trim Kit (Without Trim Pad) Single Engine 3. 4L V6, 4. 6L V8, 150HP FourStroke & OptiMax 150250HP 8M0129439 Overview The Mercury Active Trim Kit (8M0129439) gives you full automatic trim control through your VesselView display instead of a separate trim pad. Designed for single engine installations, it works with 3. 4L V6, 4. 6L V8, 150 HP FourStroke, and OptiMax 150250 HP outboards. Active Trim adjusts engine trim automatically based