Information from AudioCircuit here.
The 2a speaker specifications are:
Frequency 45-20,000Hz
Crossover 5,000Hz
Power capacity: 60 watts
Impedance: 8 ohms
Four element tweeters
Bass energized
Built in attenuator
8 inch speaker.
Photos of Electrostat 2-As (if one of these is your photo, please let me know and I'll add a credit)
(From dwillsxbr, PhotoBucket)
(From dwillsxbr, PhotoBucket)