Factor Seatpost Ostro VAM This replacement is specifically designed for use on the Factor Ostro Vam bicycle. This kit consists of the wedge, required to keep the saddle in place. Quick and easy installation. Factor Seatpost Ostro VAM This replacement is specifically designed for use on the Factor Ostro Vam bicycle. This kit consists of the wedge, required to keep the saddle in place. Quick and easy installation.