Seems to be working although I have other gadgets going on to clean up my electricity as well. I'm using one on a WiiM Ultra music streamer and another with my Fire Cube tv streamer. I'm noticing an ever so slight improvement however I concede that could be placebo. My gear is operating as well as it possibly can as far as I can tell. My main power strip has over 4000 joules protection plus I have a 2 iFi AC iPurifiers plugged in which suck up EMI and RMI if any, plus I'm using ferrite chokes all over. Plus both streaming my devices are designed to minimize interference anyways. That said I detect no noise now on either streamer. Quiet and clear. I recommend this devise because it's just a filter, no surge protection. Doubling up on surge protection isn't a good idea, may cause problems. But adding more noise filtering only will only help and not jeopardize anything assuming it's not garbage. Based on the low price of these units it's a win. The only potential negative is the size/shape depending on the situation. It's plugs in on the bottom but it's jack to plug the desired device in is on the side(not top) so it may be awkward. Also it takes up some space so it may prevent use of nearby jacks on a power strip/surge protector if they are spaced close together. Be aware.
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