The backpack has two compartments. The outside compartment that is embroidered with the Infinite Illusions logo and securely holds a piece of star foam that stores 12 yo-yos. The larger inside compartment is left empty for you to carry the rest of your stuff. On the front strap the case holds two pens or lubes, and has a detachable cell phone case that can re-attach to a belt or elsewhere. The single strap design allows you to swing the pack around, without taking it off and to access your yo-yos on the fly. The star foam keeps your yo-yos from falling out. This is the same foam we use in our Star cases, and will securely hold a yo-yo as small as a Mini-Mo and as large as a Flying Panda.