Vacuum Bag Size: 275mm*165mm(50mm)When Need to Replace the Filter bag?1.Generally,it is better to change your bag once a week if you use your vacuum 1-2 times in a week.2.Your vacuum bag starts giving a foul and musty smell.3. vacuums have an indicator light that lets you know when the bag needs to be changedHow to change the filter bag?1.Lift the release button and open the dust compartment lid upwards until it clicks into place.2.The filter bag has a flap that automatically closes to prevent dust from escaping when the bag is removed.3.Grasp the collar and remove the filter bag from the holder,Insert the new filter bag into the blue holder as far as it will go.Note: Do NOT unfold the filter bag when you take it out of the box.4.Now close the dust compartment lid until it clicks into place,take care not to catch the filter bag in the lid.If you do not insert a replacement filter bag, the dust compartment lid is designed not to close.If you have any questions, please feel free to contact us. We are committed to providing the best quality products and promise to provide 100% high-quality customer service.