The quartz insulators you see here come in a set of four. There are several applications for them – placing them under the feet of the components, on top of the components or elsewhere in your room. We found them to work their best when placed under the feet of components. Some measurable differences can also be obtained when placed above transformers of your amps and preamps so some experiment is clearly needed. Lots of reviews on them on the internet so you can read all about them when you google it.
In our store, we like the clear quartz under source components and preamps and the smoky quartz under power amps and some preamps. Tube components seems to appreciate them more than solid state components but that may have been the case of limited range of components in our store to experiment them with. So all-in-all, its an interesting accessory to try them out in your system. The quartz disc is an all natural ore so some natural elements can be seen inside the disc. Otherwise, some very minor scuff marks on the surface of the disc from components sitting on top of it. Original box included.