The Cargo Cache "Top Case" is an enclosed container for storing your passions while riding or parked and is key lockable. Reduce the risk of theft or damage to your valuables with this hard-sided unit that attaches to a standard rear bicycle rack. It gives you peace of mind knowing that your possessions are protected from the elements and securely locked away. Made of lightweight ABS plastic. It can easily hold a helmet or a laptop computer or more. For extra security removal of the Cargo Cache itself requires access to the interior and that is only accessible with the key (2 keys included). Thanks to its unique hinge, it doesn't take any extra space when opened. Come with needed hardware for instillation. The Bicycle Cargo Cache fits most rear bicycle racks (rear rack not included). A Onda "Top Case" product.