These gravity convected ovens come in three models according to volume (52 Lt, 91 Lt, and 135 Lt). CLS - Control System and PID microprocessor controller with enhanced safety features. Temperature safety exceeds DIN Class II controller. Auto-Tuning function & Bias function with internal built in re-calibration. Timer has delay ON / OFF feature (standard 99hr and 59min). Selectable measuring temperature units in °C or °F. Selectable Auto-run or Manual -run. Audible visual and audio alarm - Overtemp and Door Open. Temperature range: up to + 250° C. Incoloy sheath heating element is located at the bottom of chamber and makes for convenient repair without movement of the equipment. Other features include: 3 set-point memories, hydraulic over temperature limit, over-current fuses, door alarm. Smooth internal surface for easy cleaning. Heating element and fan stop automatically when door is opened. Viewing window and perforated shelf is optional.