The Keptel® Half Ringer Equivalant Circuit allows automatic or manual testing to be performed from the central office without interrupting service to the customer. The Half Ringer, when connected in parallel with the phone line, poses a 0.5 REN load. The Half Ringer is available in three different packages for both indoor and outdoor use and can be used in a variety of applications. Factory installation in a number of Network Interfaces Devices is available, please consult AFL Customer Service for specifics.