Slip That appeals to the inconvenience of unwanted weather and is practical for keeping shoes clean and dry. Slip That is a shoe cover that can be slipped on and then tightened over a person’s normal shoes that covers most of the ankle. It is made of a very durable Tyvek material to canopy the shoe to ensure water resistance, with rubber soles for maximum grip and security. It is an affordable means of keeping shoes safe, with a selling price of only $12.99.