Disk LED is a very small and simple application for mac that give you detail information about your any internal or external storage devices activities in a convenient summarized way.
It has so many LED models available, So user can easily choose one of them to suit your status bar style. User can also change the refresh rate of Disk LED as per your requirement. Disk LED is absolutely free of cost.
The New Disk LED Version 1.1 not only monitor the internal or external storage devices but also monitor other devices (for internal devices only). it also give you another option, where you can easily enable/disable each and every external devices.
Download : Disk LED