The Heidolph Tuttnauer autoclave is a electric sterilizer with stainless steel trays. It has four adjustable programs with temperature selections from 105 to 137 degrees C (221 to 279 F) with sterilization times up to 59 minutes for simplified and reproducible operations. The autoclave comes with stainless steel trays for maximizing space in the chamber by holding instruments, liquids, laboratory equipment and other items to be sterilized. A digital display continuously shows temperature, pressure, and running time. Every stage of the cycle is automatic and micro-processor controlled from water-fill, to sterilization, exhaust, and drying. The autoclave has a low water alarm for notifying the user when the reservoir needs to be refilled, an in-line particle filter to protect valves, and standby heating to keep the chamber warm in between cycles. The autoclave also has a combination pressure and temperature gauge, and an automatic low water shut off to prevent damage to the heating elements if there is insufficient water for sterilization. A heat-insulated, double-locking door helps protect users from accidental burns and prevents the chamber from being opened during the sterilization cycle. The autoclave has a fast or slow exhaust selection, with the fast exhaust for drying solids, and the slow exhaust for preventing media and liquid boil-over. A closed-door drying cycle maintains sterility and removes extra moisture after sterilization. A continuous pressure purge removes air pockets and ensures even sterilization, and a 3L reservoir with the drain located on top simplifies cleaning. The autoclave also has an automatic shut-off for conserving energy, and a battery backup ensures retention of settings and controls in the event of a power failure. Autoclaves are ovens that sterilize laboratory instruments and can kill bacteria, viruses or both. They are often used in laboratories to sterilize lab equipment, media and liquids, and can be designed to meet different health, safety, and environmental standards. Heidolph USA, a subsidiary of Heidolph GmbH (founded in 1938), manufactures laboratory products such as evaporators, pumps, autoclaves, shakers, stirrers, ductless hoods and workstations. The company is headquartered in Chicago, IL.