From ITS Wiki - Information Technology Services - University of Rhode Island

Public Address System (PA System)

Classroom Media Assistance has several PA Systems available for use by Instructors.
We currently have two Califone™ PA Systems, and several Microphone/Amplifier kits.

Califone™ Portable Public Address System

This is a lightweight all-in-one system that comes with the amplifying base station and a wireless "lavaliere" microphone; where the user simply clips the microphone to their clothing.
Despite its small size (about the size of two loaves of bread) it is powerful enough to hear even in the largest URI auditorium.
It's light weight and small footprint makes it easy to carry and store, as well as it is easy to operate.