1" thick. Soft foam wood-like building block are perfect for the young creative builder. Ideal for block play on the floor or in the bathtub as the blocks float and stick easily to bathtub tile walls when wet. This is the GOOD STUFF not the cheap sponge foam. These are the type of high density foam building blocks you find in classrooms, clinics, daycare centers and hospitals. Comes in a soft plastic tub. Age: 12 months & Up.