It's all in the name, very essential audio tools for your hi-fi. Better reproduction means more involvement, that is why Essential Audio Tools products are focused on the power supplied to your equipment. Only when good care is taken for the power supply, you will benefit from all details in your music. For example stray-fields and spikes coming from external (non-audio) equipment can be noticeable. Also having no earth, or having a low quality earth, can be very harmful.
The use of good quality power cords (with well designed screening), mains extension boxes (with star-wiring), checking out the phase of your mains supply and equipment and a good filtering gives the music a neutral sound and opens up many details.
The 'tools' are very well designed and manufactured. They perform great... You will be surprised!
To see how an Essential Audio Tools Socket is made, look here: