Birkenstocks Arizona Shearling-Lined size 7- 7.5 Found: the coziest riff on the world’s most comfortable sandals. Everything about these Birkenstocks, from the heather-grey felt straps to the antique pewter buckles—to the plush layer of shearling in the footbed—is peak hygge. Upper: wool felt Footbed lining: wool Sole: EVA footbed lining is no longer as fluffy as in the stock photo, no other defects.