These easy-building blocks offer all the advantages of traditional hardwood blocks...in safe, soft foam! Made of rugged, dense foam with precise edges for easy stacking, these blocks are lightweight, quiet and soft, and ensure years of safe building sessions. Each soft block is precisely related in size to the basic unit block (5 1/2"l x 2 3/4"w x 1 3/8"h), so even the youngest children can build and design with ease. Accessories sold separately.