Description + Kids can be rough on their winter gear, which is why we send them to the mountain in the Sierra Insulated Bib. This insulated, waterproof bib is equipped with reinforced hems, kick panels, and binding to withstand the season's wear and tear. And since this pant can also extend 1.5in thanks to 686's Youth Evolution feature, it withstands growth spurts too. 686 sierra insulated bib - girls'