introducing the contixo st3 stem construction engineering building blocks – a 223-piece multicolored toy designed to spark your children s creativity. this stem kit offers endless building possibilities from dinosaurs to race cars and helicopters. with plenty of tools included up to 8 kids can enjoy constructing together. ideal for ages 5 and up this engaging kit guarantees hours of educational fun fostering creativity and inspiring limitless creations for your little builders.contixo st3 stem construction engineering building blocks is a 223-piece stem toy designed to engage your children s imagination for hours. unleash your kids creativity and encourage them to build anything they put their minds to. we give you enough tools for 8 kids to build at the same time! from dinosaurs to race cars to helicopters...the possibilities are endless!at contixo we strive to help creative children in core fundamentals such as basics of physics aptitude in mechanics building and architecture.