HP D6021-69001 - Mid-plane PC board - Board that connects the I/O board, memory boards, and the processor baseboard - Mid-Plane PC Board - Board That Connects the I/O Board, Memory Boards, and the Processor Baseboard - Mounts Vertically in the Center Retail
HP 384625-001 - USB board - Includes the USB interface board, USB board frame, cable, and the audio board cables Retail
HP A6961-67105 - Midplane riser board - Has slots for the processor board, memory board, and I/O base board Retail
