These are Zobel networks and they work. I use the Stein Speaker Match with good results.
EVS Music Purifier
Rick Schultz of Tweak EVS has a new product called the Music Purifier.
Read about it here...
http://tweakaudio.com/EVS-2/EVS_Music_Purifier.html
All I can say is wow. Immediately noticeable. For only $125 these are a steal and I highly recommend them.
I have had many of these type of speaker link tweaks over the years, like EVs own Ground Enhancer, the DNM ones, and a few others. All of them did something positive but also took something away. These EVS Music Purifiers seem to be all positive and no negatives. Maybe that will change later on with more critical listening but for now I am impressed.