These are the extremely rare monoblock version, over 500W per monoblock! The Burmester 956mkII is the best deal of all Burmester amplifiers. It is pretty much the 911mk3 with less power and less expensive top cover (same size as the 911mk3, and also features X-Amp like the 909). Signature Burmester sound extreme transparency, clarity, dynamics and audiophile air. Included are the expensive $1200 monoblock adaptors to bridge them into monoblocks.