Proof for products of explosion group IIA with a maximum experimental safe gap (MESG) > 0.9 mm and a maximum operating temperature of 60 °C. Mainly used as equipment of fixed roof tanks for venting and inbreathing to prevent undue pressure resp. vacuum and undesired losses of vaporization, respectively undue emissions. Installation on top of storage vessels. Available with an explosion and endurance burning proofed condensate drain device.