The 686 Hydra Insulated Jacket is built with 10K-rated waterproofing and 10K-rated breathability to keep kids warm and dry...at the same time! ComfortZone Body Mapping insulation is strategically designed to promote free movement while junior dials in their technique and the built-in Youth Evolution tech lets the party continue through to next season. Yes, you can lengthen the sleeves in this jacket as they grow, so unless they are plowing through veggies like a farmer, you won't have to buy them a new jacket for a while.