Seat inserts and methods of manufacturing seat inserts are disclosed. Upon authentication of a user of the mobile device, the server generates the payment key, encodes the key in an image, such as a bar code, and transmits the image to the mobile device. Each of the film take-up unit and the film supply unit has a bridge, and the both bridges are movably fitted into each other. The closure is positionable between a closed position in which the flexible member is substantially proximate to the rigid member and an opened position in which the flexible member is substantially separated from the rigid member.