Kids enjoy hours of creative play with these time-honored classroom favorite unit blocks. Crafted from hardwood, which is stronger than oak, each block is finely sanded smooth to ensure it will be splinter-free. All edges are beveled and corners are safely rounded. These classically designed blocks are based on the precise unit size of 2¾" wide x 1 3/8" thick x 5½" long. 170 Pieces and 21 Shapes.