Mercury - Power Trim Cylinder Hydraulic Hose MerCruiser Sterndrive Series Braided Reinforced Construction 99904Q. Overview. Every boater knows the feeling of a trim system that responds instantly - smooth, steady, and completely predictable. It makes the whole boat feel alive beneath you, whether you're easing out of the slip at sunrise or lifting the bow to skip across open water. A reliable trim hose doesn't draw attention to itself; it simply works, every time you hit the switch. That's the r