Mercury - Tow N Stow Outboard Cover 150 Horsepower FourStroke Series Polysoft II Fabric 8M0221492. Overview. Every boater knows the feeling of stepping back from the dock and glancing at their engine one more time-just making sure everything is protected and ready. A good outboard cover gives you that sense of calm, whether you're trailering across town or settling in for a few weeks between trips. This Mercury Tow N Stow cover brings that confidence to your 150 Horsepower FourStroke. Slip it on