MINI series universal door-entry phone, compatible with most of the door-entry phones produced by leading international manufacturers. Ideal in door-entry phone system replacements and repairs. Key button and additional button for extra services with independent common. Electronic ringtone. Call volume and privacy adjustment by means of 3-position selector. Privacy function activation is indicated by a red light. Also features loudspeaker volume control and microphone volume control to meet all possible requirements, can be used in systems with positive common or systems with negative common