1,good quality with good outlooking , 2, stainless steel 304 Material: stainless steelsuitable for offices ,houses,easy installtion in the wall or on the ceiling.the valve body is equipped with a celluar gasket to form an air -tight seal . air folw is adjusted by rotating the control disc. size: 60mm, 80mm 100mm 125mm 150mm 160mm 200mm 250mm ceiling air diffuser