Please note that the replacement cones of United Windsocks are made in 2 versions: 1. WCS (Economy) version - the service life of the cone is 6-12 months. The material of the cone is taffeta fabric, from which almost all manufacturers sew. Due to the relatively short service life of taffeta cones, we supply WCS series cones with 2 cones in one package, so that the user always has a replacement cone in stock, at hand. 2. WCS/PRO version - The service life of the cone is more than 2 years. SKY DIVE material - parachute fabric of increased durability.