Replacement large power input plug for select HD and MHD Amplifiers: Fits the following models only: HD750/1 (excluding HD750/1 with Serial Numbers < #108034000001, which use HD PLUG PWR) HD1200/1 MHD750/1 (excluding MHD750/1 with Serial Numbers < #153034000001, which use HD PLUG PWR) Corresponding plug shroud on applicable amplifiers does not have phillips head screws.