This trailer hub is probably the most common used trailer wheel hub on small unbraked 750kg trailers in the UK
Grease nipple tapered roller bearing hub kit
Includes tapered roller bearings to suit a 1″ diameter shaft, 3/8UNF studs and nuts and a dust hub cap
2 bearings: 44643L for the inner and 44643 for the outer
These trailer wheel hubs are popular for use with 8 inch and 10 inch wheels if your trailer wheel has a grease nipple cut out on the centre hole.
Common sizes include: 4.80-4.00/8, 16.5/6.5-8, 5.00/10, 20.5/8.0-10, 145/80B10, 145/80R10