Does anyone know what the exact specs for the PS2 HD is?

I mean; what make? ATA 66/100/133? RPM? etc .....

Also the official internal HD comes in a special case, does that mean it sits in the bay more securely than one without?

I got a UK v7 + DMS3, so I'm planning of getting a network adaptor soon and a HD with it. Just rather have it met the same spec as the official one, in case of any problems.