Note, I originally purchased a set of these through Amazon, but returned them at the time (rejected the package). - The unit that I am reviewing was purchased directly from NVX.----------------------------------------------------------------------------------------------------------------With that disclaimer aside, I would like to note that the product works very well, and is relatively compact. - However, a very important item to note is that NVX designed this to go behind your head unit versus being directly at the amp inputs. Therefore, you will need to use couplers to change the gender of the cables (the input has a male plug, and the output is a female).In my application, I had limited space behind my head unit, and wanted it directly at my amp so I can quickly test (and remove, if needed). Therefore, I went the coupler route, since I did want to add any additional length. - Doing this, I was able to get the isolator to plug directly into the inputs of my amp (which is a 100w amp driving a set of tweeters on their own channel). - It eliminated any remaining hum/noise that I could not get rid of after redoing ALL of my ground connections (my other amps were NOT experiencing this problem). - As for any volume reduction or changes in sound quality, I have not noted any yet, but will definitely update this review if that changes.