Portable 150W compression 16 ohm speaker driver unit The driver unit, with waterproof plastic bottom cover ,solid and durable ,suitable for outdoor installation. Build-in transformer with variable power adaption. SPECIFICATIONS FHD-150 INPUT POWER 150W 16IMPEDANCE 8/16Ω FREQUENCY RESPONSE 160-3500Hz SPL at 1kHz 115dB/1W/1m TEMPERATURE RANGE -30℃ to + 70℃ THROAT COUPLING 1-3/8" - 18TPI, Throat Couple No.1 DIMENSIONS Φ145*96.5 mm FINISH Throat:Aluminum dia-cast; Case:Aluminum