The suit is a thick plastic (or whatever material it is). Very thick, no worries about ripping at all. High quality! Ill be purchasing larger sizes as we need.
Runs big. My toddler is roughly 21 lbs and 31 and we have the 18 month size (hes 17 months currently). There is still plenty of grow room & we even have to roll the sleeves up so he can use his hands.