How do I find what size wheel bearings?

[dannieboiz]

I have a Trial Rite tandem trailer. The boat is a 95 Seaswirl 2150WA

Trying to figure out what size bearing I need to purchase. The bearing buddy size is 1.98"

 

[Sandy]

This suggests you will have to access the old ones 1st , inner and outer. Click on the diagram for zoom view.:
https://www.etrailer.com/question-27088.html

 

[pdecat]

Look on the bearing for a number. Any bearing shop will have it.