Kids Mug cozy in Blue Kids Mug cozy in Blue Kids Mug cozy in Blue Scull and Cross bones fair isle mug cosy £9.50 Out of stock. One for the kids ! Skull and cross bones mug cosy , hand knitted in Rowan tweed 100% wool (guaranteed to keep things nice and warm) in a stunning red. It sits 8 cm high and slides onto the mug with just the handle peeping out. The diameter of the mug I have it sitting on is 8cm. Please hand wash and dry flat. If the cozy gets stretched a little big for the mug , then just soak in warm water , squeeze dry & dry flat into shape.