Childcraft 111 Piece Classroom Unit Blocks School Specialty Building Set, Wood Childcraft 111 Piece Classroom Unit Blocks School Specialty Building Set, Wood Based on the standard unit block size 1-3/8" x 2-3/4" x 5-1/2". An essential element of any classroom, homeschool setting, daycare, or playroom. Precisely measured and cut hardwood pieces Smooth sanded edges and corners to protect little hands. Makes a great gift that is sure to provide years of fun!