A book safe can be a simple way to hide something in plain site
Hidden dictionary design, more secret
Hide among books on a full book shelf, it would most likely go unnoticed
Books have been hollowed out to hide things for a long time
Ideal for storing valuable things like cash, jewelry... 
Steel plate and plastic materials with real paper cover
Dimension:
Small (L18 x W11.5 x H5.5)cm
Large (L24 x W15.5 x H5.5)cm