Apparel Material: The material seems to be a blend of knitted fabric (possibly cotton or synthetic fibers) with a rubberized sole, as indicated by the textured, durable sole and the stretchable, breathable upper fabric.
Size: Not specified in the image; typically, children's footwear sizes range from infant (e.g., 0-6 months) to toddler (e.g., 6-24 months) sizes, but this would need to be confirmed from the product details.