Fred wrote:
What type of battery is inside the Model 20. I need to change mine
and I understand it is behind the antenna and can be replaced without
breaking the recorder seal.

Thanks,
Fred

From Gary @ CAI:

We replace with a Panasonic CR-2330 (3v). A 2325 is also okay to use...its a
little thinner, but was the original one used in your unit. The 2330's last
longer. KEEP THE UNIT POWERED WHEN YOU REPLACE IT SO YOU DO NOT LOSE
SECURIY!!