Let me start by saying I had high hopes for these swim diapers. The description promised waterproof protection and comfort, but my experience was far from perfect.
First off, the sizing is accurate. The medium fit well around my 34-inch waist and didn't feel too tight. The material initially felt soft against the skin, which was a plus.
However, the waterproof claim completely fell apart (literally) during my first pool visit. Within minutes of entering the water, I could feel leakage - exactly what these are supposed to prevent! The stitching started coming undone after just one use.
The design is decent in theory with its wide elastic bands, but poor execution makes it useless for actual swimming. It might work better as an extra layer over regular diapers for light activities, but definitely not for water sports as advertised.
For $15-20 per piece, I expected much better quality. Save your money and look for more reliable alternatives if you actually need waterproof protection in water.