These Self Supporting Pyrometric Cones are used on a shelf, inside a kiln, to determine when a firing is complete, if the kiln provided enough heat or if there was a problem during firing. This style of cone does not require a cone holder. These Orton Cones are made from carefully controlled compositions so that they bend in a repeatable manner over a very small temperature range. When the cone tip reaches a point level with the base it indicates it is properly fired. Cones have been used in ceramic firings for more than 100 years and Orton has the history and experience to provide the very best product. This offer includes two boxes of 25 cones each for a total of 50 cones. The number of this cone is 06 which bends at an approximate temperature of 1873 degrees fahrenheit depending on firing conditions.