12 pieces with inlaid letters. Pieces with tongue and groove.Slide from the starting position ALBWHITE CK!!ET TO !WHITE !BLACK! On the back there is a slide up and down. This slide changes the free hole.Then slide to BLACK! WHITE! easy?Material Acrylic.
Exchange SLIDING. with PUZZLES The center piece can only slide up and down. Pieces cannot fall out through the transparent top plate. More assignments on the back of the puzzle. Material MDF.
