Substitution for other 300B tubes:
Since Western Electric is pretty much what all the hype of 300B sound is about – this Linlai™ WE300B replica is a 1:1 replica of original Western Electric 300B, can substitutes all standard 300B tubes.
It cannot be used to replace a 300B tube with 2.5V heater voltage (commonly referred as 300B 2.5V). A standard 300B has heater voltage of 5V, not 2.5V. If your amp uses 300B 2.5V (very few amps on the market does so!), usually this is identified in the amp manual. If you are not sure, check with your amp manufacturer!
If your amp uses a Chinese 300B-98, that is a standard 5V heater voltage standard 300B tube and can be replaced by Linlai™ WE300.