Hi folks, I looked in the optacon 2 user's manual and in the specifications section it says: operating Environment temperature 5 to 35 degrees Celsius, or 41 to 95 degrees Fahrenheit relative humidity 10 to 90 percent There you have it; I'm surprised they didn't mention this in Optacon R1 manuals but maybe they didn't think of it at the time. Mary to view the list archives, go to: www.freelists.org/archives/optacon-l To unsubscribe at any time, just send a message to: optacon-l-request@xxxxxxxxxxxxx with the word "unsubscribe" (without the quotes) in the message subject. Tell your friends about the list. They can subscribe by sending a message to: optacon-l-request@xxxxxxxxxxxxx with the word "subscribe" (without the quotes) in the message subject.