Sector Antenna ID

How can I tell difference between a 90deg and 120deg sector antenna when it’s already mounted on a tower? I don’t see any part numbers readily visible. Do have to take it off air and the radio off to see a part #? Thanks

Cambium part number      Antenna Type                           Gain (dBi)
 
C050900D003A                 5 GHz Sector Antenna           90 degree 15
C050900D002A                 5 GHz Sector Antenna          120 degree 15
C024900D004A                 2.4 GHz Sector Antenna       90 /120 degree 15

Yes, you have to take it off air to see a part #

If you got rid of the box you can not find the part #, the only thing on the antenna is a serial number.