20-Watt Public Address Amplifier 20W at 4 to 16 Ohms and 25 / 70V Three inputs (2 mic and telephone or 1 mic, 1 auxiliary and telephone) Built in circuit provides microphone precedence over the auxiliary channel when a customer supplied SPST switch is actuated Telephone input is signal activated and automatically mutes the auxiliary channel during a page 11.5 in. W x 7.5 in. D x 3 in. H