APPLICATIONS:Combined supply and extract ventilation systems for various premises where high air flow at relatively low system resistance is required. MOTOR:The motor is equipped with ball bearings. SPEED CONTROL:Both smooth and step speed control is performed with the thyristor or autotransformer controller. Several fans can be connected to one controller in case the total power and operating current do not exceed the rated controller values. Mounting:fan is installed into the duct by means of clamps or directly inside the wall. Colour: Black Material: iron package contents: 1 * Exhaust fan Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.