Retain up to 6 months (or 5000 alerts) of alert and sensor data on your NetBotz 500 with the NetBotz 500 Extended Storage System, which combines the Extended Storage software with a 60GB external USB hard drive. Graphs can cover up to 6 months rather than the standard 24-hour limit. If the NetBotz 500 is rebooted, the data is retained since disc storage is persistent. A mounting bracket and USB cable for the drive are included.APC NetBotz Extended Storage System 60GB with Bracket