How do I determine which size to get?

To make sure your Carpio will fit perfectly, please measure your palm - it's easy and fast. 
Size Width
Small < or exactly 9 cm (3,54 '')
Large > 9 cm (3,54 '')

Take a ruler and measure your palm's width, as shown in the picture above. 
If the width is below 9 cm, choose Carpio S, otherwise choose Carpio L.