Aerad Chart...help Pls

[nouseforaname]

Hi,

i'm just looking at an Aerad En Route Low Alititude chart.

Can anyone tell me what the * after e.g. FL75* means?

Because on alot of them it says something like this:

e.g. A47 FL65 FL75* but what does the * mean....is it the lowest available FL for that airway and FL65 the base of the airway?

Many thanks,