NEC EXPRESS 320Lb-R - Manual (Page 30)

1-16 Precautions for Use
Make sure that your options are compatible with the system. If you attach any incompatible
option, there is a risk of malfunction that could lead to a breakdown.
It is recommended to use NEC's genuine option products. Some competitors’ products are
compatible with this server. However, servicing for trouble or damage resulting from such a
product will be charged even within the warranty period.