Two Source, 6.5", Amplified Drop Ceiling Speaker on a 2X2 Full Grill with backcan delivers up to 40 watts power directly to the speaker. Each powered speaker (2X2FG-R2S61) can drive three additional speakers (2X2FGIC6NA). One line can drive up to 10 self-amplified speakers. Lower noise feature and protection from shorts and overheating. 15 Volt DC Level 5 power supply included and optional Volume Control available. Available also in bluetooth models.