Or go to a trailer-specific company and they can help get you the correct bearings. You most likely have a 6-lug hub with your trailer being a single axle and carrying an H200. I have an H180 with a 6-lug single axle trailer.
The 6-lug hubs (heavier axle load) are quite different than the standard 5-lug bearings that every Academy, WalMart, Autozone, etc. seem to carry.
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1999 180 Horizon OB Fisherman Pkg
San Antonio, TX
Choice of tow vehicle:
'93 Explorer 4x4 (sold)
'05 Grand Cherokee 4x4 w/ 5.7 Hemi (member of the 240k+ mile club!)