Its is rated at 150W RMS Max ( Root Means Square - this is a true power rating

With both channels driven with a 1 KHZ Signal and 30 minutes at 90% power there is ZERO degrade . No distortion and no fall off . Its truly amazing

150 W Rms Max Power

You will need cables to put signal in, this is normally Phono cables , it has Six inputs and of course can accept a Bluetooth receiver ( Not included ) for wireless use .

6 Inputs Phone Type with and Vinyl MM Use Included and an option for MC boards and Bluetooth

The basic weight is 9 KGS ( 20 Lbs ) seriously heavy ( no compromise for real power but a traditional transformer ) The size is 430MM ( 17 inch ) by 45mm ( 1.8 inch ) high by 300mm ( 12 Inch ) .. It can be stood on end and it can be hidden from sight if desired ..Its perfect for any discrete installation - Or its look great by itself.

9 KGS ( 20 Lbs )

430MM Wide ( 17 inch ) x 45mm ( 1.8 inch ) high by 300mm ( 12 Inch ) deep

It has an ability to drive anything from 16 Ohm Speakers all the way down to 2 ohm speakers .. It has a unique heatsink where the whole case is its cooling and as such can drive serious loads .. All speaker will work well

Ideal will be 4 Ohm - 16 Ohm Speakers

Its totally flat at 20hz to 22 khz no degrade, no distortion, and no loss ..Click this link its the best way to described it .

https://oa21.com/videos/v/oa21-specs

This is easy - 100% Yes You have not heard music, until its through a fantastic amp