Kids wooden educational toy blcoks -EN-71,ASTM F963,ST,ICTI, ... of the smallest parts is 4.5cm and thickness is 2.25cmSpecially designed for 1-year-old children,but only 30 ... and so on, 30 pcs is enouh, when they were 2-3 years old konwing the concept of building , adding 100 ... you get any question ,please contact us at your convenience Kids wooden Educational toys building blocks