Model HD72W is a cost effective assembly that include high-quality 8" speaker, 70.7V/25V transformer and screw type grill. Unit is shipped assembled, ready for installation.The HD72W features a conventional cone design speaker with a 1" diameter voice coil to reproduce voice and music with excellent response and superb overall performance.The HD72W includes a factory mounted dual voltage transformer that exhibits less than 1.5dB of insertion loss and a frequency response of +1.5dB from 100Hz - 10kHz. Speaker / transformer is factory installed on a 62-8 style baffle.