www.wgtcaddy.com and you can check on youtube for EASY installation
Slow greens....................Distance +/- incline x 1.2 = strength needed
Standard greens.............Distance +/- incline x 1 = strength needed
Fast greens......................Distance +/- incline x 0.9 = strength needed
Very fast greens...............Distance +/- incline x 0.84 = strength needed
Tournament greens....... Distance +/- incline x 0.77 = strength needed
Legend greens ...............Distance +/- incline x 0.72 = strength needed
Championship greens...Distance +/- incline x 0.67 = strength needed
Round up and you should be ok.