The TNF243 with Sentry 12-Key Controller is a round, top loading Insulating FireBrick Kiln with groove mounted Elements. It measures 22.5″dia x 29″D inside. The TNF243 Kiln is rated to 2350°F. It fires on 240 Volt / 1 Phase and uses a NEMA 6-50P Cordset. Drop Down Switchbox. Rated to 11500 Watts.