About this item:
If you have a vintage TouchTone telephone, typically pre 1986, you need to have a polarity guard installed to insure that you will be able to dial out. The vintage TouchTone telephones required polarity to be correct, ,meaning positive must be positive, negative must be negative. If the polarity is reversed, it disables vintage TouchTones.
Since the mid 1980's, telephones have had the polarity guards built in. Because of this, the phone company rarely pays attention to polarity anymore. This means you have a 50-50 chance your phone will work. Installing a polarity guard will insure trouble free dialing. Installing is easy and I send along complete instructions. I'm also available to help via phone or messaging.