The wrench is well-built and worked very well for my 2006Yamaha F150. In my case, the outboard has been used on a freshwater lake since new so I didn't have any corrosion to deal with. A little tricky to use since one must keep the AMT0306 very flat against the cylinder caps while simultaneously turning the cheater bar used on with the socket wrench. In the end, the AMT0306 made short work of cap removal and installation.