Usha Crisp Air 250mm Exhaust Fan (Pearl White) Sweep size mentioned in product title is the dimension (diameter) of the blade. It should not be the sole criterion for you to make a purchase decision. Before buying an exhaust fan, it is important to consider a few other factors such as the dimensions of the duct (length, width), available space around the duct from the ceiling or side walls, whether installation is done on glass or concrete wall, etc. Accurate knowledge of the duct dimensions will help you make precise comparisons with the dimensions provided in the image. This will best serve your purpose and make your purchase seamless.