The puzzle has four pieces that loosely speaking resemble tuning forks bent into an L shape.  The pieces interlock into a base which has slots cut into it.

The process to get them all out of the base takes 25 steps; and then you have to work that in reverse to get them back in again. You will need to have made 13 directional moves from the starting position before you can even get the first piece out. 

Metal puzzle

Difficulty 7/10

Age 10+