This may seem like an ordinary clock. However, there is a hidden compartment within the shell. It requires two moves to solve the puzzle. I designed this clock to resemble a traditional Japanese puzzle box. To set the time or replace the battery on the clock, you have to solve it in order to unlock the compartment. No glue is needed for assembly. Compatible with the Bambu Clock Kit. One AA battery is needed. Look to the model photos for assembly guide.