These are the most common fairleads for UTV/SXS' and  ATV's.

Most ATV's run a 4-7/8 (4.875 inch") fairlead.

Most UTVs with a 4000, 4500, 5000, 5500, or 6000 LB winch run a 6 inch fairlead. (Unless you are running a narrow drum winch)

The 6.5 inch hawse fairlead is for the Harbor Freight Badland Winch.