L&L School-Master kilns are under warranty for FIVE YEARS! They are super-durable and include all of the easy maintenance features of the Easy-Fire kilns. For simplicity, however, School-Master Kilns feature the intuitive One-Touch™ kiln control that has a standard Bisque and Glaze program designed to fit the needs of most K-12 school programs. Temperature, heating and cooling rate, delay time and soak time can all be easily modified for the two main programs and remain set that way until deliberately changed. In addition, for more advanced users, there are four custom programs. The control is single zone and the kilns have graded elements. Since there are only two sizes L&L has tuned the element resistance for good performance. The School-Master kilns are limited to Cone 6 operation even though the construction of the kilns can handle higher temperatures.