Product#: TG-2180 Availability: This item normally ships within 1 - 2 business days. Description: Can be used to perform evaporations on a hot plate or over an open flame. They are modeled to the same radius of curvature for convenience stacking. The heavy wall and uniform fire-polished edge provide mechanical strength. The outside diameter cannot be controlled within close limits and a slight degree of out-of-round can be expected to occur.