Hi Thanks for the reply. The PN is 434811-b21. It is basically the same as an MSA70 with 25 horizontal 2.5" drive slots 2U. The rear has 2 PS, 2 fan and 2 I/O slots. The I/O module is 4 port SAS with 2 battery backup module slots PN 411153-001, the BB module is 406099-001. I searched all these...