The Slip-N-Grip Plastic Seat Cover Advantage: The top (outside) layer of the seat cover is smooth, so porters and service technicians can "slip" in and out of the vehicle easily, allowing the to work faster without the need for extra caution. The bottom (inside) layer of the seat cover is formulated with a high friction plastic so that it can "grip" itself into place. This layer keeps the product in place for continued protection.