NVM-1CH 3 Layer Hepaflo Filter Dust Bag. Pneumatic high efficiency HEPA-FLO disposable filter bags are suitable for all Henrys Hetty James and Pneumatic NRV200 vacuum cleaners. They are up to 14 times more efficient than paper bags in retaining fine dust within the bag. These replace paper bags NVM-1C/2 and NVM-1C/3. Includes 10 Dust Bags High Efficiency 3 Layers.