These are the 3.1 security class laboratory ovens available in different models with natural ventilation. The outside body is made with strong steel coated with epoxy paint and inside cavity is made of stainless steel. The oven has two doors system for good temperature thermal protection. A 45 mm hole is present on the backside of the oven for releasing exhaust with a adjusting device for opening and closing of that outlet. And a 10 mm hole is present on the top of the oven body for placing or inserting a probe or thermometer. A timer watch which can be set from 0 to 12hrs+infinite.