ARTONE ceiling speaker CS-600 is best for audio control contractor, 70v pa loudspeaker with 2-way 6-inch coaxial speaker, it comes with multi-tap power 40W/20W/10W at 100 volt and 20W/10W/5W at 70 volt line, and compatible with 8 ohm low impedance speaker line. 4-pin euroblock terminal allows speaker wires connect and loop connect to subsequent speakers.