Doll/Test top-loading kilns come in one size only: 11" diameter by 9" high. Typically they work on 120 volts, although a version is available for 200-240 volts. The 120 volt versions are available in either 15 amp Cone 5 version or a 18 amp Cone 6 version. 200-240 versions are rated to Cone 10. There is a choice of two controls: The One-Touch™ intuitive control or the more sophisticated 24-Key DynaTrol.