The ThinkPad Carrying Case - Expander model provides notebook protection with flexible expansion at a great value. It features a clamshell design made of durable, lightweight water-resistant nylon. The Expander model can handle more than just your ThinkPad. Its expanding compartment is spacious enough to support a portable projector, printer, or even a second notebook. Or, you could use the expanding compartment for a few overnight items when traveling.