The Bothy Slipper is a basecamp-inspired mule with high-traction rubber sole that can be worn both outdoors and indoors. Berghaus Footwear Size Guide. Fleece lining. Elastic cuff. EU 39.5 40 40.5 41.5 42 42.5 43 44 44.5 45 45.5 46.5 47 47.5 48.5.