The GM814 runs on 240v - requires 27.8 amp breaker. Inside dimensions 18" x 18" x 13.5" deep, 2. cubic feet. Glassmaster conroller gives you GlassFire Mode allowing you to write a program simply by choosing your technique and the speed. Write your own firing programs with up to 8 Segments using Ramp and Hold. Now you can store up to 8 programs. Adjust temperatures or hold times while the kiln is firing using Add Time or Add Temp or simply select Anneal Now to set your project and begin annealing it. Fires to 1800 degrees fahrenheit. Instruction manual, and warranty card included. Two-year warranty.