Each CD Carousel comes with a USB cable and an AC power adapter. Multiple carousels can be connected together using a USB hub (or hubs) and each carousel requires AC power. As many as 127 CD Carousels (with a total capacity of 19,050 disks!) can be connected together to create one huge library which you can search and access from a single database on your PC. Imagine being able to find any disk among a library of thousands in just a few seconds! With the CD Carousel you can!