A blank ring can be added to an Olympic Electric or Glass kiln but it will lower the temperature range. Blank rings come with stainless steel band and handles if applicable. 18/18H electric kilns can add a wired ring which includes an element that will maintain the kiln's maximum temperature. Amperage will be added to the kiln which may require a larger size breaker.
Blank rings dimensions are the inside width of the kiln by 4.5" deep.