Replacement small power input plug for select HD and MHD Amplifiers: Fits the following models only: HD600/4 HD900/5 HD750/1 (excluding HD750/1 with Serial Numbers > #108034000001, which use HD PLUG PWR2) MHD600/4 MHD900/5 MHD750/1 (excluding MHD750/1 with Serial Numbers > #153034000001, which use HD PLUG PWR2) Corresponding plug shroud on applicable amplifiers has phillips head screws