I have a 2017 Mercury 20HP 4 stroke, serial number OR770686. When I bought it new 3 years ago, it came with a prop on it. I looked at all the paperwork in the file, but the size and pitch of the prop are not on any of the paperwork. I went on Mercury Marines website and looked up the motor, but they do not give the prop description anywhere. The prop selector was not any help either. I want to pick up a spare prop to have just in case I hit a rock or stump. Unfortunately, the motor is in storage right now and I will not have access to it for another week or two. Do any of you know what prop I have on that motor? Thanks in advance!