ArcwegRash Guard Men Short Sleeves Shirt UPF 50+ Elastic Rash Vest Loose Fit Swimming Top Quick Drying Running Vest Sports Top

Is the sizing in the drop down menus us sizing, eu sizing or cn sizing? all i can see in the size chart is the sizing for shorts not t shirts.

A size chart that relates to the product (rash vest) rather than shorts would help.

Can someone please add a size chat for the t shirts?

Is this allowed to use in the swimmming pool?