Spec Sheet Preview: The AA926 industrial master station is designed for indoor or outdoor use and is weather resistant. The AA926 provides for either handset or loudspeaking use, when receiving a call. For handset use, add the optional (model GD509) handset. The optional model 306-8 external speaker can also be used with the AA926. The AA926 is designed to work with the RM5000EX and/or CB901EX series microprocessor intercom systems.