Modular sliding storage box system for storage of all kinds of long objects. After unlocking the system, the storage box is pulled out by hand for about 45% of its length, after which the storage box should supported on the sliding support (VS), to enable it to be pulled out to about 95%of its length. When pushed in, the box is automatically locked in place. The unit can also be fitted with an optional roof structure (mezzanine). It is possible to sub-divide the compartments in the cassettes using adjustable pins.