Technical details
| Type |
Bezel panel |
| Number of hard drives supported |
4 |
| Hard drive interface |
Serial ATA, Serial Attached SCSI (SAS) |
x3550 M4 plus 4x 2.5" HDD Assembly Kit
Option 81Y6657 upgrades models with four hot-swap HDD bays to eight hot-swap HDD bays. Model A2x requires H1110 to be replaced by M1115 or M5110 to support eight HDDs. An optical drive can be installed internally when this option is used.