Next Grey Borg Slipper Boo. The label states the size as a Large (UK 7-8 / EU 41-42). They are made from a super-soft, curly synthetic textile Grey Borg (fleece) designed to mimic plush sheepskin or shearling. A pull-on ankle bootie style with an incredibly cozy lining and an integrated security tab connection stitched at the rear collar cuff.