Mektronic Engg. Co. Manufactures Petri Dish Warmer with Temperature Display. Mektronic Engg. Co also manufactures various types of medical and surgical instruments. The Petri Dish Warmer with Temperature Display has cavities which can accommodate four Petri dishes at a time. The Petri Dish Warmer with Temperature Display has auto cut-off on set temperature and PID controlled of heating. This Warmer has Voltage of 230V A.C.