Choose the perfect fit by measuring your hand circumference. Measure your dominant hand with a tape around the widest part of your palm where the thumb starts at the palm, not including the thumb. If you are between sizes or have a thick palm, choose the larger size.SizeM(middle finger: 8cm, width of palm: 9.5cm, total length: 23cm)L(middle finger: 8.5cm, width of palm: 10cm, total length: 24cm)XL(middle finger: 9cm, width of palm: 10.5cm, total length: 25cm)Please note that the fabric of shell is waterproof, but it is not suitable for dipping gloves into water for a long time because the seams and tips of the thumb and index finger is not waterproof.