These Stratos Monoblocks include upgrades that in Klaus’s (Odyssey manufacture) words place them closer in design to his top of the line Kismet amplifier. Upgrades include the Kismet power supply, black circuit board (Odyssey’s top board), and upgraded capacitors. These amps where purchased by the seller for $4000.00 a year and half ago. In their price range (and likely twice their price range) the Odyssey amplifier is an exceptional amplifier both in terms of build quality and sonic signature. Amps will be shipped in manufactures boxes with manuals.