Nordost Quantum QRT QX4 Power Purifiers. Add 4% if paypal is used.
Lots of great reviews:
The Qx4 employs the same high quality machined casework and socket options (15A IEC input, US, Schuko or UK AC output) as the Qx2, but is twice as powerful, containing four QRT field generator modules. Also like the Qx2, it does not limit voltage swing or reduce the impedance of the AC supply.
Qx4 is ideally used either individually to feed a complete system, or in multiple arrays in the most demanding applications. Adding additional units in a carefully considered way will produce even greater Quantum effects, the whole being greater than the sum of the parts.
Dimensions (WxHxD): 10.6" x 3.15" x 7.7"
Weight (Net): 11 lbs.
Input: 15A IEC