From the inside out -200g of PrimaLoft Bio insulation and a B-DRY waterproof membrane the Sphinx Mid is at home in ice-laden mountain towns Featuring waterproof oiled nubuck leather, recycled components, and a Vibram Arctic Grip A.T. sole made of Vibram XS Trek. From the inside out -200g of PrimaLoft Bio insulation and a B-DRY waterproof membrane -the Sphinx Mid is at home in ice-laden mountain towns. Featuring waterproof oiled nubuck leather, recycled components, and a Vibram Arctic Grip A.T. sole made of Vibram XS Trek.