New in package Spio compression orthosis flexible bracing. This was ordered for my daughter and we did not end up using it. I think she was about 7-8 years old and of average size when it was ordered (just giving you an idea of the size since the Spio's size numbers are confusing). Each child is going to be different so it may fit a 5 year old, it may fit a 10 year old.  Take measurements with your child lying down and the chart is in CENTIMETERS. If you are between numbers the chart says to round up. SS 60 is 60 centimeters across the nipple line when measuring. It is chest circumference so go all the way around the chest at the nipple line. This is a tight fit and offers great support to the core and torso area. The shirt has rubber around the inside bottom to keep it in place better. It zips up the back to get on and off easier. Material is a silky smooth polyester feel like athletic leggings. Shirt is brand new and has never been washed. I recommend hand washing this in mild detergent with no fabric softener when needed. The material tends to snag. My daughter has had quite a few Spio items and they all snagged so it most likely will as your child wears it.  Hand washing will keep it looking better longer. Questions just ask and I will answer as best as I can. Please do not buy without measuring your child first. I do not accept returns. 

Photo of the child with the shirt on in the white back ground is not my photo or shirt. I included it to show you the fit on.