An older key system for small businesses, the Pro-XL was build in several different configurations. These systems are still found in operation and although dated, used handsets and KSU components are available for purchase for those that need to replace broken equipment. The Pro-XL 1032 came with the ability to connect to six CO lines with eight phones, but could be expanded by adding telephony card to a total of 32 telephones.
Asuzi Pro-XL 616 Installation Manual
Asuzi Pro-XL 1032 Installation Manual
Asuzi made the Pro series, a key style business telephone system in several configurations. Most of their systems were 6 by 8 size key systems that would connect to CO lines.