Mariasplunge, Brf is correct.
And though there may be several other top notch mfg'ers of excellent line conditioning I too am only aware of one that meets all of these criteria. I've been using them since 2001 and when I became a dealer a few years ago I was proud to represent their product line. Their older models were quite possibly the best. Their latest models are only about 3 times better.
Anyway, I was not going to mention the mfg'er's name lest anyone think I was a shill. (And please never look at somebody's virtual system.)
But frankly I'm amazed after all these years how even some of the most seasoned in the industry can know so little about proper line conditioning.
Once an enthusiast has listened extensively to even a modest system utilizing proper line conditioning it's pretty tough to go back and listen to any system not utilizing proper line conditioning for more than just a few minutes before ear fatigue settles in.
It's like driving a Ferrari F30 on 82 octane. Well..., I imagine that's what it would be like.
-IMO