Originally designed in collaboration with the Museum of Arts and Design, in NYC (thus the "MAD"), this open-ended building toy is made up of 12 beech hardwood blocks in a hardwood storage tray. Six of the blocks are 1.5 inch cubes and six are rounded/quarter-circle shapes. They can be stacked and arranged in a surprising number of interesting ways. 

Natural, unvarnished hardwood. 10 x 3.75 x 1.6 in. A wonderful first blocks set, safe for children 1 year and up.