Features: High Quality Roof Ventilator is sturdy, durable and made from high quality weather resistant materials. It offers the performance of standard roof venting systems but in a slimline, low profile finish which is designed to release trapped air in your roof space. This Roof Ventilator is a dependable rotary unit that works automatically, continuously and silently without operating or maintenance costs. Premium-grade stainless steel dual ball bearings with integrated molded shield to protect bearing raceway. Internally and externally braced; permanently lubricated ball bearings. Ideal for residential or light commercial use. Specification: Stainless steel turbines fit any roof. 100% new and high quality. Material: stainless steel. Size: L: 270mm x 240mm x 200mm (10.6" x 9.4" x 7.9"). M: 270mm x 240mm x 150mm (10.6" x 9.4" x 5.9"). Diameter: 150mm / 200mm. Weight: 758g / 26oz. Colour: Silver. Package Content: 1 x Roof Ventilator