They have been designed to obtain the best compromise between the heating speed and the operating life of both the resistances and the thermal insulation. The combination of preformed ceramic fiber panels, low density refractory bricks, and high quality resistances, allow to these oven a rise in temperature and a very rapid cooling thus having great advantages in the work with intermittent kiln. The structure in fire-painted steel with epoxy paints, and support feet with rubber base, make the ovens of the LKN series compact, light and that can be placed on any laboratory table or bench. The heating part is made up of resistors made with spring-shaped Khantal-type wire and mounted on ceramic glow plugs with the exception of the LKN 77 and 87 models, where the resistors are in silicon carbide “and of the LKN 78 – LKN 79 – LKN 80 models – LKN 88 -LKN 89 -LKN 90 where the resistances are in “molybdenum disilicide”. In the back there is a chimney for the escape of any gases that could form during the cooking phases.