Our kids lab coat is design for 3 years old and up. The photo featured is 19 months old for reference point. The material is thick and not see through. 

Material:  The fabric is 65%polyester 35%cotton

Sizing:

XS-  age 3-5 years old for kids 105-115cm (3.44''-3.77'')
S- age 5-8 years old for kids 116cm-125cm (3.8''-4.1'')