NSP-E350B4U/NSP-B350W4U USB 4Bay Drive Enclosure

(ASI SKU 51102 Black, SKU 51103 White)

The four drive external enclosure, AKA B4044U or Cyber Box, supports JBOD "spanning" of two or four PATA IDE hard drives (does not support RAID 0): http://www.nspiregear.com/404.asp
If you cannot find the printed manual in the box there will be one on the CD. Also the link to the ODM PDF manual is here (some slight differences): http://www.asisupport.com/B4044U_Manual.pdf
However the NSpire version is slightly different. The dip switches that control the spanning modes are in a single bank and have three settings:

MD2 = 2 HDD mode which combines the two channel 1 drives as one large disk and the other channel as one large disk.

MD1 = 1 HDD mode which combines all 4 disks as one large disk

MD0 = Separate 4 HDDs (no spanning)