Alesis M1 Active MK3, Active 2-way bi-amp studio monitor, Woofer: 5 ""(127 mm) 40 Watt aluminum woofer, Tweeter: 1 ""(25 mm) 25 Watt silk tweeter, Amplifier: 65 watts RMS bi-amp Class A / B power amp, Frequency range: 45 - 22,000 Hz, Inputs: balanced XLR / jack combi input, Protection circuits: overheating