Our 50 piece Unit Block sets are made of select yellow pine. Each block is hand-cut, belt-sanded, edge-routed and then hand-sanded. They are smooth but left unfinished which provides just enough friction to make tall structures more stable. The standard unit of our blocks is 1 3/8” by 2 3/4” by 2 3/4”. Our sets contain 15 different shapes come in wheeled storage canisters. For ages 12 months to adult!