Which size should my child have? 05 December 2019 13:10 Updated Size 70-170 is available in our kids and youth assortment. The size indicates the length of the child in centimeters. You can find a chart of all the sizes under the section size guide. Related articles How does the "Extend size" work? When do I need to reimpregnate my Didriksons jacket? How do I contact you? Want to exchange for a different product or size? What do you mean by fully waterproof?