Pyrometric Cones For Monitoring Ceramic Kiln Firings-Cone 06 (1 Pkg/50) Usable in cone holders or kiln sitters Most accurate way to control ceramic firing Consistent results Orton has been manufacturing since 1896 Please note that the cones can come in pairs that need to be split apart. The box will come in 25 sets that when split apart is 50 cones. This is done by the manufacturer to reduce the number of cones broken during shipping.