PSU - Power Supply Units. PDU - Power Distribution Unit. QR490A HP 3PAR 2.5INCH M6710 STORAGE EXPANSION. This item has been professionally refurbished. You may also be interested in.Join our Newsletter for the latest products and special offers! This item is in the category "Computers/Tablets & Networking\Enterprise Networking, Servers\Network Storage Disk Arrays\SAN Disk Arrays". The seller is "techbuyer_usa_outlet" and is located in this country: US. This item can be shipped to United States.