Get on Amazon.com : http://www.amazon.com/gp/product/B00LM6LIDO?tag=clothingattes-20

Seagate NAS 4-Bay Diskless Network Attached Storage Drive (STCU100)

Centralize your storage to allow PC Mac computers and mobile devices in your business to access collaborate and share files
Backup all your PC and Mac computers to a single centralized location including support for Time Machine software
Up to 100BMs file transfer performance secure cost-effective alternative to cloud backup services
Includes Seagate NAS optimized drives for increased performance and reliability
Seagate 4-Bay Network Attached Storage NAS 0TB Diskless with 4 empty bays You supply your own compatible hard drives