Beka's Little Builder Block Sets feature a unique block shape - a block with notches that unit flats can fit into. The combination of notched blocks and unit flats allows block play to proceed horizontally, as well as vertically. The addition of blocks that may be interlocked provides added stability to towers, giving young children increased positive play experiences. Our Little Builder Block Sets make great stand alone sets; they are also often added to our Traditional Block Sets to create bigger and better sets for families who already have unit blocks in their home. Recommended age: 1+ years