Prop Question

Joined
May 16, 2012
Location
Bloomington, MN.
#1
I am still a newbie to all this but I am in need of a new prop and I took my old prop off just to check it out. It said it was a 13 1/2 x 17. So does that mean I have to find a 13 1/2" prop? And 17 is the pitch? Also I have heard of high and low pitch numbers which is which? One is for torque and one is for speed.