Herring Fergus rubber-soled slippers in Black - Herring Sale. Fergus is a super-warm fleece-lined slipper with wool lining, suede uppers and a rubber sole. As a moccasin design it is also more supportive than a mule slip-on. Please note you may have to go up a size due to the wool lining. Upper: Suede. Sole: Rubber-soled. Features: Casual styles, Slip ons, Rubber-soled, handmade, Moccasins, Slippers, Warm lined, Mens, Slippers. Herring Shoes Fergus rubber-soled slippers