Compatible models HD-WHU3/R1 series Interface Compliant with SerialATA 3.0 Specification Disk medium 3.5 type Operating voltage 5V±5%, 12V±10% (supplied from main unit) Energy Consumption Efficiency (revised April 2011) OP-HD4.0WH C division 0.0018 OP-HD3.0WH C division 0.0031 OP-HD2.0WH C division 0.0036 *Energy consumption efficiency is the power consumption measured by the measurement method specified by the Energy Conservation Law divided by the storage capacity specified by the Energy Saving Law External dimensions (width x height x depth) *main unit only (excluding protrusions) 102 x 27 x 147mm Weight about 740g Operating environment Conforms to compatible products Green Purchasing Law (revised April 2011) OP-HD4.0WH Yes OP-HD3.0WH Yes OP-HD2.0WH Yes Compliant with RoHS Directive Main accessories Instruction manual *Warranty is listed on the package