OEM:
9492 and 9496
A2/435 and A2/436
 
A pair of bearings to suit Norton hubs from the early 1930s right through until the late 1950s including all cotton reel hubs and most single sided drum hubs - please check compatibility below. 
 
Compatibility
These bearings fit the front and rear hub on the following models: 
Model 1 (Big 4)
16H
Model 18
Model 19
Model 20
Model 50
Model 55
ES2
CS1
CJ
Post-war Model 30 & 40 International
 
They also fit the rear hub only on pre-war Model 30 & 40 Internationals