The laboratory preheating furnaces of the RETOMAT range are especially designed for precious and non-precious alloys and partial frameworks. They are available in three chamber sizes 2.8 l (RETOMAT MINI), 5.5 l (RETOMAT) or 8.6 l (RETOMAT MG) and can be fitted with either a "Comfort" or an "Easy" controller. With the basic economical "Easy" controller, the required temperature is kept constantly until the device is being switched off. The "Comfort" controller allows for precise temperature control with programmable parameters of temperature increase speed and hold times. 14 programs and a speed program with calendar function and real time are included for this purpose. Temperature stays evenly in the chamber because of the four-sided element and optimum chamber insulation. The furnace door is upward opening for increased safety. Once being removed from the furnace, hot casting rings can be positioned on a useful tray which is available as an optional extra.