What drive belt size do I need for Honda Harmony 2113 Hydrostatic riding mower?

What drive belt size do I need for Honda Harmony 2113 Hydrostatic riding mower?

Added (1). The drive belt snapped and pieces broke off upon removal and all of the numbers are worn off. I can't seem to find anywhere the drive belt size I need.

I tried to look it up and i'm seeing 2 different sizes…1/2" X 107 or 109…
This should be the part number 22431-771-700
Also found the manual: )
http://cdn.powerequipment.honda.com/pe/pdf/manuals/31771710.pdf