VAC AERO hot zones have unitized construction for easy removal and maintenance. Lightweight design with low thermal mass and inertia for faster quenching and long life. Work Load Size: Standard sizes from small laboratory units up to 54” wide x 54” high x 72” deep. Larger models available. Heating Elements: Customer’s choice of lightweight curved graphite, pure or lanthanated molybdenum strip. Hearth: Constructed with quickly removable hearth rails of pure molybdenum designed to support uniformly distributed loads of up to 4000 lbs at 2400°F.