I don't recall the part #s. Most 3.5 are interchangeable across 813, 82x, 836, 846, and 847. Make sure it has the drive activity LED. Some of them don't have that.
The Aluminum ones that come on 743/745 are recessed and may not be compatible.
If you are not fully populating all the 16 bays, either use the dummies or put masking tape on the vents of the empty trays to direct the airflow over the drives.
I have 16x coraid branded ones which came off a 836 chassis and know they work. If you are planning to get the front bezel, they will not work.
