The MASK4T loudspeaker Black / White has a unique innovative design and its transparent sound offers incredible intelligibility ideal for background music and paging purposes. MASK4T can be used in low impedance 16 ohms (up to 4 loudspeakers in parallel on a standard 4 ohms amplifier channel) or in 100 volt with several power tappings (20 – 10 – 5 – 2.5 watts).