Addonics NAS Storage Tower is a family of high performance Network Attached Storage system made of a unique combination of the Addonics familiy of Storage Tower and the latest high performance, feature rich NAS 4.0 adapter, Unlike other NAS storage solutions in the market, the Addonics NAS Storage Tower is designed for easy upgrade and expansion. The storage unit can be attached directly to any system for data transfer. You can also add more storage to the LAN by simply attaching another RAID Tower, any eSATA or hard drive to the second storage port on the NAS 4.0 adapter, In fact you can even add up to as many as sixteen storage devices onto the LAN via the NAS 4.0 adapter by using simple USB hub or Port Multiplier! Unlike other NAS product in the market, drives are easily removed or added on the fly without restarting the storage unit, making the operation similar to a drive cartridge system on a network. 

The hard drives, the RAID controller inside the Storage Tower and the NAS adapter (the Network Attached Storge control module) are all easily replaceable or upgraded to newer models as technology advances. You add your choice of hard drives or update the hard drives to larger capacity ones as your storage requirement grows.via the convenient removable drive system in the storage unit